Fix a wrong paint worklet layout test expectation

There are actually two problems in this test:
1. The expectation file is wrong, when canvas context.fillRect takes
int as size, not '50px'.
2. The test file needs parseInt to convert string to it.

This CL fixes the test.

Bug: 1096078
Change-Id: I01e6a753d3d9772a39dfacfe8b87f80b6f877b88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2254449
Reviewed-by: Kevin Ellis <kevers@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780773}
diff --git a/css/css-paint-api/paint-function-arguments-ref.html b/css/css-paint-api/paint-function-arguments-ref.html
index 6391d17..764c8f3 100644
--- a/css/css-paint-api/paint-function-arguments-ref.html
+++ b/css/css-paint-api/paint-function-arguments-ref.html
@@ -32,9 +32,8 @@
   context.fillRect(40, 40, width, width);
 };
 
-drawCanvas('box-1', 'rgb(50, 100, 150)', '50px');
-drawCanvas('box-2', 'rgb(150, 100, 50)', '100px');
-
+drawCanvas('box-1', 'rgb(50, 100, 150)', '50');
+drawCanvas('box-2', 'rgb(150, 100, 50)', '100');
 </script>
 </body>
 </html>
diff --git a/css/css-paint-api/paint-function-arguments.https.html b/css/css-paint-api/paint-function-arguments.https.html
index fc303bf..c613bd1 100644
--- a/css/css-paint-api/paint-function-arguments.https.html
+++ b/css/css-paint-api/paint-function-arguments.https.html
@@ -36,7 +36,7 @@
     static get inputArguments() { return ['<color>', '<length>']; }
     paint(ctx, geom, properties, args) {
         ctx.fillStyle = args[0].toString();
-        let size = args[1].toString();
+        let size = parseInt(args[1].toString());
         ctx.fillRect(40, 40, size, size);
     }
 });