Extract method: CreateDelegatedLayerForFrameProvider

Embedders may want to apply independent filters on layers for their
browser GUI. If they need two instances of a GUI element then they are
forced to add two layers with the same content in them. In the DRL case
an access to DelegatedFrameProvider needed. With this change embedders
can create secondary DRL layers easily.

https://groups.google.com/a/chromium.org/forum/
    /#!topic/graphics-dev/xZPzMnBe6dg

R=sievers@chromium.org,aelias@chromium.org
BUG=

Review URL: https://codereview.chromium.org/527073002

Cr-Commit-Position: refs/heads/master@{#294146}

content/browser/renderer_host/render_widget_host_view_android.cc

@@ -411,6 +411,19 @@ void RenderWidgetHostViewAndroid::GetScaledContentBitmap(
       src_subrect, dst_size, result_callback, color_type);
 }
 
+scoped_refptr<cc::DelegatedRendererLayer>
+RenderWidgetHostViewAndroid::CreateDelegatedLayerForFrameProvider() const {
+  DCHECK(frame_provider_);
+
+  scoped_refptr<cc::DelegatedRendererLayer> delegated_layer =
+      cc::DelegatedRendererLayer::Create(frame_provider_);
+  delegated_layer->SetBounds(content_size_in_layer_);
+  delegated_layer->SetIsDrawable(true);
+  delegated_layer->SetContentsOpaque(true);
+
+  return delegated_layer;
+}
+
 bool RenderWidgetHostViewAndroid::HasValidFrame() const {
   if (!content_view_core_)
     return false;
@@ -869,11 +882,8 @@ void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
   DCHECK(compositor);
   DCHECK(frame_provider_);
   scoped_refptr<cc::DelegatedRendererLayer> delegated_layer =
-      cc::DelegatedRendererLayer::Create(frame_provider_);
-  delegated_layer->SetBounds(content_size_in_layer_);
+      CreateDelegatedLayerForFrameProvider();
   delegated_layer->SetHideLayerAndSubtree(true);
-  delegated_layer->SetIsDrawable(true);
-  delegated_layer->SetContentsOpaque(true);
   compositor->AttachLayerForReadback(delegated_layer);
 
   readback_layer = delegated_layer;

content/browser/renderer_host/render_widget_host_view_android.h

@@ -251,6 +251,9 @@ class CONTENT_EXPORT RenderWidgetHostViewAndroid
       gfx::Rect src_subrect,
       const base::Callback<void(bool, const SkBitmap&)>& result_callback);
 
+  scoped_refptr<cc::DelegatedRendererLayer>
+      CreateDelegatedLayerForFrameProvider() const;
+
   bool HasValidFrame() const;
 
   void MoveCaret(const gfx::Point& point);