Flood-fill the canvas used for layout tests

content/shell/renderer/test_runner/WebTestProxy.cpp

Index: content/shell/renderer/test_runner/WebTestProxy.cpp
diff --git a/content/shell/renderer/test_runner/WebTestProxy.cpp b/content/shell/renderer/test_runner/WebTestProxy.cpp
index 1a999e48ddf70297cbab64b29e3446477d921c5b..879cbd91b1ca3f3667d24226f095f4ba3e706e83 100644
--- a/content/shell/renderer/test_runner/WebTestProxy.cpp
+++ b/content/shell/renderer/test_runner/WebTestProxy.cpp
@@ -633,6 +633,7 @@ SkCanvas* WebTestProxyBase::canvas()
     int scaledWidth = static_cast<int>(ceil(static_cast<float>(widgetSize.width) * deviceScaleFactor));
     int scaledHeight = static_cast<int>(ceil(static_cast<float>(widgetSize.height) * deviceScaleFactor));
     m_canvas.reset(skia::CreateBitmapCanvas(scaledWidth, scaledHeight, true));

[reed1, 2014/01/08 15:49:17]

I think you want to just pass 'false' to CreateBitmapCanvas. Otherwise, you
claiming to skia that all the pixels will be opaque, which tells skia to ignore
reading the alpha values during compositing.

By passing false, skia will flood-fill the pxiels with zero for you (and
potentially faster than you can, when we start using calloc. WIth 'false', you
won't need to call drawARGB().

[jochen (gone - plz use gerrit), 2014/01/08 18:03:52]

Done.

+    m_canvas->drawARGB(0, 0, 0, 0);
     return m_canvas.get();
 }