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

cc/single_thread_proxy.cc

Index: cc/single_thread_proxy.cc
diff --git a/cc/single_thread_proxy.cc b/cc/single_thread_proxy.cc
index 91ac9520dd780d09804535fc3962a793fd1a3fce..dd3a505a4ded477fd826eb8026899afdf4d8e0e1 100644
--- a/cc/single_thread_proxy.cc
+++ b/cc/single_thread_proxy.cc
@@ -8,6 +8,7 @@
 #include "cc/draw_quad.h"
 #include "cc/layer_tree_host.h"
 #include "cc/output_surface.h"
+#include "cc/picture_pile_impl.h"
 #include "cc/resource_update_controller.h"
 #include "cc/thread.h"
 
@@ -404,4 +405,11 @@ bool SingleThreadProxy::commitPendingForTesting()
     return false;
 }
 
+scoped_refptr<PicturePileImpl> SingleThreadProxy::capturePicturePile()
+{
+    // Requires impl-side painting, which is only supported in threaded compositing.
+    NOTREACHED();
+    return scoped_refptr<PicturePileImpl>();
+}
+
 }  // namespace cc