Implement a method to access the non-composited content root layer picture pile.

cc/single_thread_proxy.h

Index: cc/single_thread_proxy.h
diff --git a/cc/single_thread_proxy.h b/cc/single_thread_proxy.h
index 6be5e97a5285b9fae77e42fb1031a255009e8843..fb898808f3066e795e1fceb3c324a1128474d5e9 100644
--- a/cc/single_thread_proxy.h
+++ b/cc/single_thread_proxy.h
@@ -15,6 +15,8 @@
 namespace cc {
 
 class LayerTreeHost;
+class PictureLayer;
+class PicturePileImpl;
 
 class SingleThreadProxy : public Proxy, LayerTreeHostImplClient {
 public:
@@ -46,6 +48,7 @@ public:
     virtual void acquireLayerTextures() OVERRIDE { }
     virtual void forceSerializeOnSwapBuffers() OVERRIDE;
     virtual bool commitPendingForTesting() OVERRIDE;
+    virtual scoped_refptr<PicturePileImpl> capturePicturePile(const PictureLayer* layer) OVERRIDE;
 
     // LayerTreeHostImplClient implementation
     virtual void didLoseOutputSurfaceOnImplThread() OVERRIDE { }