cc: GPU rasterize to an auxiliary surface when using MSAA renderbuffers

cc/resources/resource_provider.h

Index: cc/resources/resource_provider.h
diff --git a/cc/resources/resource_provider.h b/cc/resources/resource_provider.h
index bd395bf053da162e29629e8018297c06de9dd9d5..9b130b853e9176475b10b8599f31176d22b592cd 100644
--- a/cc/resources/resource_provider.h
+++ b/cc/resources/resource_provider.h
@@ -347,6 +347,7 @@ class CC_EXPORT ResourceProvider
     SkSurface* sk_surface() { return sk_surface_.get(); }
 
     gfx::Size GetResourceSize() const { return resource_->size; }
+    ResourceFormat GetResourceFormat() const { return resource_->format; }
 
     void UpdateResourceSyncToken(const gpu::SyncToken& sync_token) {
       set_sync_token_ = true;
@@ -678,7 +679,7 @@ class CC_EXPORT ResourceProvider
   // A process-unique ID used for disambiguating memory dumps from different
   // resource providers.
   int tracing_id_;
-
+  friend class GpuRasterizer;
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };