don't create SkDevice directly, use SkBitmap or (better) SkCanvas::NewRaster factory

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index e4122821f489e6e7858f59946a6b783345c8c9d6..bd1e3ca85759476405ee40ff892720d13a44f4b8 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -95,8 +95,7 @@ class OnDemandRasterTaskImpl : public internal::Task {
   // Overridden from internal::Task:
   virtual void RunOnWorkerThread(unsigned thread_index) OVERRIDE {
     TRACE_EVENT0("cc", "OnDemandRasterTaskImpl::RunOnWorkerThread");
-    SkBitmapDevice device(*bitmap_);
-    SkCanvas canvas(&device);
+    SkCanvas canvas(*bitmap_);
     picture_pile_->RasterToBitmap(
         &canvas, content_rect_, contents_scale_, NULL);
   }