cc: Do bitmap conversion for RasterBuffer in the worker thread.

cc/resources/resource_provider_unittest.cc

Index: cc/resources/resource_provider_unittest.cc
diff --git a/cc/resources/resource_provider_unittest.cc b/cc/resources/resource_provider_unittest.cc
index 9c47cb2dc437b9c782d3b5626236d24791dab825..eb6cb42a205bcf6a44f9e2033d11650121d34c7c 100644
--- a/cc/resources/resource_provider_unittest.cc
+++ b/cc/resources/resource_provider_unittest.cc
@@ -952,8 +952,11 @@ TEST_P(ResourceProviderTest, TransferSoftwareResources) {
       size, GL_CLAMP_TO_EDGE, ResourceProvider::TextureUsageAny, format);
   uint8_t data3[4] = { 6, 7, 8, 9 };
   SkImageInfo info = SkImageInfo::MakeN32Premul(size.width(), size.height());
-  SkCanvas* raster_canvas = child_resource_provider_->MapImageRasterBuffer(id3);
-  raster_canvas->writePixels(info, data3, info.minRowBytes(), 0, 0);
+  RasterCanvas* raster_canvas =
+      child_resource_provider_->MapImageRasterBuffer(id3);
+  raster_canvas->GetSkCanvas()->writePixels(
+      info, data3, info.minRowBytes(), 0, 0);
+  raster_canvas->Flush();
   child_resource_provider_->UnmapImageRasterBuffer(id3);
 
   scoped_ptr<base::SharedMemory> shared_memory(new base::SharedMemory());
@@ -2938,8 +2941,8 @@ TEST_P(ResourceProviderTest, PixelBufferLostContext) {
                                GL_INNOCENT_CONTEXT_RESET_ARB);
 
   resource_provider->AcquirePixelRasterBuffer(id);
-  SkCanvas* raster_canvas = resource_provider->MapPixelRasterBuffer(id);
-  EXPECT_TRUE(raster_canvas == NULL);
+  RasterCanvas* raster_canvas = resource_provider->MapPixelRasterBuffer(id);
+  EXPECT_TRUE(raster_canvas->GetSkCanvas() == NULL);
   resource_provider->UnmapPixelRasterBuffer(id);
   resource_provider->ReleasePixelRasterBuffer(id);
   Mock::VerifyAndClearExpectations(context);
@@ -3069,9 +3072,10 @@ TEST_P(ResourceProviderTest, Image_Bitmap) {
   SkBitmap bitmap;
   bitmap.allocN32Pixels(size.width(), size.height());
   *(bitmap.getAddr32(0, 0)) = kBadBeef;
-  SkCanvas* canvas = resource_provider->MapImageRasterBuffer(id);
-  ASSERT_TRUE(!!canvas);
-  canvas->writePixels(bitmap, 0, 0);
+  RasterCanvas* canvas = resource_provider->MapImageRasterBuffer(id);
+  ASSERT_TRUE(!!canvas->GetSkCanvas());
+  canvas->GetSkCanvas()->writePixels(bitmap, 0, 0);
+  canvas->Flush();
   resource_provider->UnmapImageRasterBuffer(id);
 
   {
@@ -3195,9 +3199,10 @@ TEST_P(ResourceProviderTest, CopyResource_Bitmap) {
   SkBitmap bitmap;
   bitmap.allocN32Pixels(size.width(), size.height());
   *(bitmap.getAddr32(0, 0)) = kBadBeef;
-  SkCanvas* canvas = resource_provider->MapImageRasterBuffer(source_id);
-  ASSERT_TRUE(!!canvas);
-  canvas->writePixels(bitmap, 0, 0);
+  RasterCanvas* canvas = resource_provider->MapImageRasterBuffer(source_id);
+  ASSERT_TRUE(!!canvas->GetSkCanvas());
+  canvas->GetSkCanvas()->writePixels(bitmap, 0, 0);
+  canvas->Flush();
   resource_provider->UnmapImageRasterBuffer(source_id);
 
   dest_id = resource_provider->CreateResource(