Use an up-to-date canvas size when building canvas filters

When canvas filters specify a filter primitive subregion
(e.g. by specifying a width or height), filter building
depends on having an up to date canvas size; otherwise,
the crop rect computed for the filter is incorrect.

This CL directly passes the canvas size to filter building
code, rather than having the filter builder use a size
from the layout tree, since the latter might be stale.

BUG=561045

Review URL: https://codereview.chromium.org/1583103007

Cr-Commit-Position: refs/heads/master@{#370047}

2 files changed, 24 insertions, 0 deletions

diff --git a/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height-expected.html b/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height-expected.html
new file mode 100644
index 0000000..0e23e3f
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height-expected.html
@@ -0,0 +1,7 @@
+<canvas id="canvas" width="100" height="100"></canvas>
+<script>
+var canvas = document.getElementById('canvas');
+var ctx = canvas.getContext('2d');
+ctx.fillStyle = '#0f0';
+ctx.fillRect(0, 0, 50, 40);
+</script>
diff --git a/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height.html b/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height.html
new file mode 100644
index 0000000..1185895
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/fast/canvas/canvas-filter-width-height.html
@@ -0,0 +1,17 @@
+<svg style="display: block; width: 0; height: 0">
+  <defs>
+    <filter id="crop" primitiveUnits="objectBoundingBox">
+      <femerge x="0" y="0" width="50%" height="40%">
+        <femergenode in="SourceGraphic"></femergenode>
+      </femerge>
+    </filter>
+  </defs>
+</svg>
+<canvas id="canvas" width="100" height="100"></canvas>
+<script>
+var canvas = document.getElementById('canvas');
+var ctx = canvas.getContext('2d');
+ctx.filter = 'url(#crop)';
+ctx.fillStyle = '#0f0';
+ctx.fillRect(0, 0, 90, 90);
+</script>