/tests/content/media/test/test_streams_element_capture.html is failing on our testing machines when enabling D2D 1.1 canvas. It does not seem to fail for me locally.

In the test, we create a canvas, draw the last frame of the video to it, then use canvas.getImageData on pixel 0,0 and test for alpha == 255. This works for all the movies except for gizmo.mp4. In gizmo.mp4 case, canvas.getImageData of 0,0 pixel once the movie ends is 78,51,32,0 so the test fails.

I imagine an issue with SourceSurfaceD2D1...

Or, now guessing DrawTargetD2D1:OptimizeSourceSurface...

So it appears on Windows 7, Direct2D has a bug where it will not properly ignore the alpha channel of a source surface when drawing using a brush. When using DrawBitmap however, this is fine. This breaks the test because the decoder will give us a B8G8R8X8 image with the alpha channel set to 0x00. As a work-around we can use DrawBitmap. This should cover all of our usecases since only canvas currently uses DrawSurface. I've added an assert to remind us if we try using it elsewhere with 'opaque' images.