Add debug shortcuts that toggles options to shows paint rects

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 5777d65e89f89d31b5d8804954e578c982f1336a..10c6979992d312d8d13e4b2c1346684c624d3f76 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -31,6 +31,7 @@ class RunLoop;
 namespace cc {
 class ContextProvider;
 class Layer;
+class LayerTreeDebugState;
 class LayerTreeHost;
 }
 
@@ -363,6 +364,9 @@ class COMPOSITOR_EXPORT Compositor
 
   bool IsLocked() { return compositor_lock_ != NULL; }
 
+  const cc::LayerTreeDebugState& GetLayerTreeDebugState() const;
+  void SetLayerTreeDebugState(const cc::LayerTreeDebugState& debug_state);
+
  private:
   friend class base::RefCounted<Compositor>;
   friend class CompositorLock;