Merge 236625 "Use SkBitmap backing instead of GDI backed platfor..."

cc/resources/bitmap_content_layer_updater.cc

Index: cc/resources/bitmap_content_layer_updater.cc
===================================================================
--- cc/resources/bitmap_content_layer_updater.cc	(revision 246699)
+++ cc/resources/bitmap_content_layer_updater.cc	(working copy)
@@ -65,8 +65,12 @@
     devtools_instrumentation::ScopedLayerTask paint_setup(
         devtools_instrumentation::kPaintSetup, layer_id_);
     canvas_size_ = content_rect.size();
-    canvas_ = skia::AdoptRef(skia::CreateBitmapCanvas(
-        canvas_size_.width(), canvas_size_.height(), layer_is_opaque_));
+    bitmap_backing_.setConfig(
+        SkBitmap::kARGB_8888_Config,
+        canvas_size_.width(), canvas_size_.height(),
+        0, layer_is_opaque_ ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
+    bitmap_backing_.allocPixels();
+    canvas_ = skia::AdoptRef(new SkCanvas(bitmap_backing_));
   }
 
   base::TimeTicks start_time =