Simplify platform_canvas.h by recognizing that PlatformCanvas does not actually extend

skia/ext/bitmap_platform_device_win.cc

Index: skia/ext/bitmap_platform_device_win.cc
===================================================================
--- skia/ext/bitmap_platform_device_win.cc	(revision 165342)
+++ skia/ext/bitmap_platform_device_win.cc	(working copy)
@@ -268,6 +268,15 @@
   return bitmap_device;
 }
 
+// PlatformCanvas impl
+
+SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,

[sky, 2012/11/01 17:41:39]

On windows we need to support creating with the BitmapPlatformDevice and
SkDevice. See skia.gyp where it excludes platform_canvas_win when use_aura == 1
and use_canvas_skia are set.

[reed1, 2012/11/01 21:07:21]

Not sure what you're saying. I have also also updated platform_canvas_skia.cc to
work with the new interface. Did I miss a try-bot or test to catch what you are
referring to?

[sky, 2012/11/01 21:44:57]

Windows has two configurations. One uses PlatformCanvasSkia, the other uses
PlatformCanvasWin. Which one is used is controlled by the use_aura GYP_DEFINE. I
believe your code forces using PlatformCanvasWin always. The win_aura bot should
build this configuration. I'm not sure that using PlatformCanvasWin always would
cause a failure, but it would certainly cause lots of unnecessary allocations.

+                             HANDLE shared_section, OnFailureType failureType) {
+  SkDevice* dev = BitmapPlatformDevice::Create(width, height, is_opaque,
+                                               shared_section);
+  return CreateCanvas(dev, failureType);
+}
+
 // Port of PlatformBitmap to win
 
 PlatformBitmap::~PlatformBitmap() {