diff --git a/html/canvas/element/compositing/2d.composite.clip.clear.html b/html/canvas/element/compositing/2d.composite.clip.clear.html
index 0c353f5d6b3288..b990e32b541417 100644
--- a/html/canvas/element/compositing/2d.composite.clip.clear.html
+++ b/html/canvas/element/compositing/2d.composite.clip.clear.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.clear</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.copy.html b/html/canvas/element/compositing/2d.composite.clip.copy.html
index afc73376ccbf01..960b59cd79f708 100644
--- a/html/canvas/element/compositing/2d.composite.clip.copy.html
+++ b/html/canvas/element/compositing/2d.composite.clip.copy.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.copy</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.destination-atop.html b/html/canvas/element/compositing/2d.composite.clip.destination-atop.html
index 82e6e1a9ceb5d5..113c9d04de09ca 100644
--- a/html/canvas/element/compositing/2d.composite.clip.destination-atop.html
+++ b/html/canvas/element/compositing/2d.composite.clip.destination-atop.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.destination-atop</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.destination-in.html b/html/canvas/element/compositing/2d.composite.clip.destination-in.html
index 519dec749a48fb..325fa7198b7973 100644
--- a/html/canvas/element/compositing/2d.composite.clip.destination-in.html
+++ b/html/canvas/element/compositing/2d.composite.clip.destination-in.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.destination-in</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.destination-out.html b/html/canvas/element/compositing/2d.composite.clip.destination-out.html
index 95c6be7846714e..4774edf25f4b1d 100644
--- a/html/canvas/element/compositing/2d.composite.clip.destination-out.html
+++ b/html/canvas/element/compositing/2d.composite.clip.destination-out.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.destination-out</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.destination-over.html b/html/canvas/element/compositing/2d.composite.clip.destination-over.html
index f3b83e30f984c7..2474403233754c 100644
--- a/html/canvas/element/compositing/2d.composite.clip.destination-over.html
+++ b/html/canvas/element/compositing/2d.composite.clip.destination-over.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.destination-over</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.lighter.html b/html/canvas/element/compositing/2d.composite.clip.lighter.html
index 87ddf2865728d3..9cc05d68b0c7fd 100644
--- a/html/canvas/element/compositing/2d.composite.clip.lighter.html
+++ b/html/canvas/element/compositing/2d.composite.clip.lighter.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.lighter</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.source-atop.html b/html/canvas/element/compositing/2d.composite.clip.source-atop.html
index be9ccbdad4bb1d..3698cf5363e993 100644
--- a/html/canvas/element/compositing/2d.composite.clip.source-atop.html
+++ b/html/canvas/element/compositing/2d.composite.clip.source-atop.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.source-atop</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.source-in.html b/html/canvas/element/compositing/2d.composite.clip.source-in.html
index e1837904637c55..b54bd07cb9a744 100644
--- a/html/canvas/element/compositing/2d.composite.clip.source-in.html
+++ b/html/canvas/element/compositing/2d.composite.clip.source-in.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.source-in</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.source-out.html b/html/canvas/element/compositing/2d.composite.clip.source-out.html
index e943a7eb21d0f3..11b66cfab75ac1 100644
--- a/html/canvas/element/compositing/2d.composite.clip.source-out.html
+++ b/html/canvas/element/compositing/2d.composite.clip.source-out.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.source-out</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.source-over.html b/html/canvas/element/compositing/2d.composite.clip.source-over.html
index fa5054311c204f..55d217c6744b2b 100644
--- a/html/canvas/element/compositing/2d.composite.clip.source-over.html
+++ b/html/canvas/element/compositing/2d.composite.clip.source-over.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.source-over</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.clip.xor.html b/html/canvas/element/compositing/2d.composite.clip.xor.html
index 3464088c48eec4..fb4e3df65f5707 100644
--- a/html/canvas/element/compositing/2d.composite.clip.xor.html
+++ b/html/canvas/element/compositing/2d.composite.clip.xor.html
@@ -27,8 +27,7 @@ <h1>2d.composite.clip.xor</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
 
 });
 </script>
diff --git a/html/canvas/element/compositing/2d.composite.uncovered.image.copy.html b/html/canvas/element/compositing/2d.composite.uncovered.image.copy.html
index 245b7ecd7a08df..bdb3de546c5695 100644
--- a/html/canvas/element/compositing/2d.composite.uncovered.image.copy.html
+++ b/html/canvas/element/compositing/2d.composite.uncovered.image.copy.html
@@ -29,7 +29,6 @@ <h1>2d.composite.uncovered.image.copy</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/element/compositing/2d.composite.uncovered.image.destination-atop.html b/html/canvas/element/compositing/2d.composite.uncovered.image.destination-atop.html
index 3e624ce23e0f71..b294010d8d1189 100644
--- a/html/canvas/element/compositing/2d.composite.uncovered.image.destination-atop.html
+++ b/html/canvas/element/compositing/2d.composite.uncovered.image.destination-atop.html
@@ -29,7 +29,6 @@ <h1>2d.composite.uncovered.image.destination-atop</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/element/compositing/2d.composite.uncovered.image.destination-in.html b/html/canvas/element/compositing/2d.composite.uncovered.image.destination-in.html
index cc6019c7157cb8..03bb30602f337d 100644
--- a/html/canvas/element/compositing/2d.composite.uncovered.image.destination-in.html
+++ b/html/canvas/element/compositing/2d.composite.uncovered.image.destination-in.html
@@ -29,7 +29,6 @@ <h1>2d.composite.uncovered.image.destination-in</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/element/compositing/2d.composite.uncovered.image.source-in.html b/html/canvas/element/compositing/2d.composite.uncovered.image.source-in.html
index 791e2f877d8d35..1e23ead09600c9 100644
--- a/html/canvas/element/compositing/2d.composite.uncovered.image.source-in.html
+++ b/html/canvas/element/compositing/2d.composite.uncovered.image.source-in.html
@@ -29,7 +29,6 @@ <h1>2d.composite.uncovered.image.source-in</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/element/compositing/2d.composite.uncovered.image.source-out.html b/html/canvas/element/compositing/2d.composite.uncovered.image.source-out.html
index 794fa254abfb24..fa0bc40b309f34 100644
--- a/html/canvas/element/compositing/2d.composite.uncovered.image.source-out.html
+++ b/html/canvas/element/compositing/2d.composite.uncovered.image.source-out.html
@@ -29,7 +29,6 @@ <h1>2d.composite.uncovered.image.source-out</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.clear.html b/html/canvas/offscreen/compositing/2d.composite.clip.clear.html
index ba555feeb94b05..7bf385e0002f50 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.clear.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.clear.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.clear</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.clear.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.clear.worker.js
index abae05ac241219..ba85656feb1cb5 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.clear.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.clear.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.copy.html b/html/canvas/offscreen/compositing/2d.composite.clip.copy.html
index 061a2560034a99..053ab46ed77786 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.copy.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.copy.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.copy</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.copy.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.copy.worker.js
index dfebd98a6b7016..f6ec2a5f0a716d 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.copy.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.copy.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.html b/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.html
index 19b05ef098a2ef..54089dc47100ee 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.destination-atop</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.worker.js
index 9c8fa79c5aadcb..19459117b51a37 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-atop.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.html b/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.html
index f57414616d51bb..5aa3ae5eb232c6 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.destination-in</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.worker.js
index a98624f82485eb..b0b1c71abb31c3 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-in.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.html b/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.html
index bdf8c7bc905c4d..8b201109b82935 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.destination-out</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.worker.js
index 0cf915d1c7796d..3fad74e4739182 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-out.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.html b/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.html
index 4c484b667df162..47b99c2e87f137 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.destination-over</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.worker.js
index b1b5eee6f4e124..9e5cb738a474e5 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.destination-over.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.lighter.html b/html/canvas/offscreen/compositing/2d.composite.clip.lighter.html
index 8a1ed3f2149276..2c1d60bbaba624 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.lighter.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.lighter.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.lighter</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.lighter.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.lighter.worker.js
index 8576d9db7c4c77..5da6bb8602d9ad 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.lighter.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.lighter.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.html b/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.html
index 0bc3e975e29d32..9fe31e892ece91 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.source-atop</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.worker.js
index fd220f52b3ce87..21aa591ca34f1a 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-atop.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-in.html b/html/canvas/offscreen/compositing/2d.composite.clip.source-in.html
index f91862bf707445..a8ae684294a24d 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-in.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-in.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.source-in</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-in.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.source-in.worker.js
index 0c61fb77945630..ea9d5b64d01abd 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-in.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-in.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-out.html b/html/canvas/offscreen/compositing/2d.composite.clip.source-out.html
index b93ebf368d0cb2..2284d05b424d57 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-out.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-out.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.source-out</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-out.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.source-out.worker.js
index ec57663af18a87..97d85978745e7e 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-out.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-out.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-over.html b/html/canvas/offscreen/compositing/2d.composite.clip.source-over.html
index 90125c003a1c95..98ec1da6a40e0e 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-over.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-over.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.source-over</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.source-over.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.source-over.worker.js
index 15c322ee597db0..e4ff4a3dd835f4 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.source-over.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.source-over.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.xor.html b/html/canvas/offscreen/compositing/2d.composite.clip.xor.html
index d35b53c9e44304..102b3857fc2376 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.xor.html
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.xor.html
@@ -28,8 +28,7 @@ <h1>2d.composite.clip.xor</h1>
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 
 });
diff --git a/html/canvas/offscreen/compositing/2d.composite.clip.xor.worker.js b/html/canvas/offscreen/compositing/2d.composite.clip.xor.worker.js
index 30bae44aa995c3..d3b39219810467 100644
--- a/html/canvas/offscreen/compositing/2d.composite.clip.xor.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.clip.xor.worker.js
@@ -23,8 +23,7 @@ t.step(function() {
   ctx.clip();
   ctx.fillStyle = '#f00';
   ctx.fillRect(0, 0, 50, 50);
-  _assertPixel(canvas, 25,25, 0,255,0,255);
-  _assertPixel(canvas, 75,25, 0,255,0,255);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
   t.done();
 });
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.html b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.html
index cf0ff7ecbb14cb..566e5abb477d84 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.html
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.html
@@ -23,7 +23,6 @@ <h1>2d.composite.uncovered.image.copy</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.worker.js b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.worker.js
index a2588c33868292..e93962ce6d6eb9 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.copy.worker.js
@@ -17,7 +17,6 @@ promise_test(async t => {
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.html b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.html
index cf588f08617c81..0e014c80f3d39b 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.html
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.html
@@ -23,7 +23,6 @@ <h1>2d.composite.uncovered.image.destination-atop</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.worker.js b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.worker.js
index d220d0e9b9424f..3cea3620424f87 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-atop.worker.js
@@ -17,7 +17,6 @@ promise_test(async t => {
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.html b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.html
index 7a9fa65e397c14..3a3ac4a400c3ad 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.html
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.html
@@ -23,7 +23,6 @@ <h1>2d.composite.uncovered.image.destination-in</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.worker.js b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.worker.js
index e605dd9fcc6902..d96c112d646362 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.destination-in.worker.js
@@ -17,7 +17,6 @@ promise_test(async t => {
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.html b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.html
index 0b1c7ac29d21d6..0b54d39320c649 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.html
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.html
@@ -23,7 +23,6 @@ <h1>2d.composite.uncovered.image.source-in</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.worker.js b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.worker.js
index 1e8b877dffa87e..5b6bad7d38c2ed 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-in.worker.js
@@ -17,7 +17,6 @@ promise_test(async t => {
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
 done();
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.html b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.html
index 35b89af55c2cd7..bae97a6779f50b 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.html
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.html
@@ -23,7 +23,6 @@ <h1>2d.composite.uncovered.image.source-out</h1>
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
diff --git a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.worker.js b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.worker.js
index d42c271dc5cebc..fa44cb7556de19 100644
--- a/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.worker.js
+++ b/html/canvas/offscreen/compositing/2d.composite.uncovered.image.source-out.worker.js
@@ -17,7 +17,6 @@ promise_test(async t => {
   const blob = await response.blob();
   const bitmap = await createImageBitmap(blob);
   ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-  _assertPixelApprox(canvas, 15,15, 0,0,0,0, 5);
   _assertPixelApprox(canvas, 50,25, 0,0,0,0, 5);
 }, "drawImage() draws pixels not covered by the source object as (0,0,0,0), and does not leave the pixels unchanged.");
 done();
diff --git a/html/canvas/tools/yaml/element/meta.yaml b/html/canvas/tools/yaml/element/meta.yaml
index 44db64521d304b..091f61147df62c 100644
--- a/html/canvas/tools/yaml/element/meta.yaml
+++ b/html/canvas/tools/yaml/element/meta.yaml
@@ -169,9 +169,8 @@
     const blob = await response.blob();
     const bitmap = await createImageBitmap(blob);
     ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-    @assert pixel 15,15 ==~ %s +/- 5;
     @assert pixel 50,25 ==~ %s +/- 5;
-    """ % (dest, op, to_test(expected0), to_test(expected0)),
+    """ % (dest, op, to_test(expected0)),
                 'expected': """size 100 50
     cr.set_source_rgba(%s)
     cr.rectangle(0, 0, 100, 50)
@@ -239,8 +238,7 @@
     ctx.clip();
     ctx.fillStyle = '#f00';
     ctx.fillRect(0, 0, 50, 50);
-    @assert pixel 25,25 == 0,255,0,255;
-    @assert pixel 75,25 == 0,255,0,255;
+    @assert pixel 50,25 == 0,255,0,255;
     """ % (op),
                 'expected': 'green'
         } )
diff --git a/html/canvas/tools/yaml/offscreen/meta.yaml b/html/canvas/tools/yaml/offscreen/meta.yaml
index 384992a4824776..f6cfa90955c84a 100644
--- a/html/canvas/tools/yaml/offscreen/meta.yaml
+++ b/html/canvas/tools/yaml/offscreen/meta.yaml
@@ -151,9 +151,8 @@
     const blob = await response.blob();
     const bitmap = await createImageBitmap(blob);
     ctx.drawImage(bitmap, 40, 40, 10, 10, 40, 50, 10, 10);
-    @assert pixel 15,15 ==~ %s +/- 5;
     @assert pixel 50,25 ==~ %s +/- 5;
-    """ % (dest, op, to_test(expected0), to_test(expected0)),
+    """ % (dest, op, to_test(expected0)),
             } )
 
     for (name, src, dest) in [ ('uncovered.nocontext', (255, 255, 0, 1.0), (0, 255, 255, 0.5)) ]:
@@ -207,8 +206,7 @@
     ctx.clip();
     ctx.fillStyle = '#f00';
     ctx.fillRect(0, 0, 50, 50);
-    @assert pixel 25,25 == 0,255,0,255;
-    @assert pixel 75,25 == 0,255,0,255;
+    @assert pixel 50,25 == 0,255,0,255;
     t.done();
     """ % (op),
         } )