Make cc::CompositorFrames movable [Part 1 of 2]

cc/output/compositor_frame.h

Index: cc/output/compositor_frame.h
diff --git a/cc/output/compositor_frame.h b/cc/output/compositor_frame.h
index e5e0c660f6faeb3930d5f3339bb686b380e605bd..50eacc3701edff2cfe586ca366a6a86c5272e370 100644
--- a/cc/output/compositor_frame.h
+++ b/cc/output/compositor_frame.h
@@ -21,14 +21,15 @@ namespace cc {
 class CC_EXPORT CompositorFrame {
  public:
   CompositorFrame();
+  CompositorFrame(CompositorFrame&& other);
   ~CompositorFrame();
 
+  CompositorFrame& operator=(CompositorFrame&& other);
+
   CompositorFrameMetadata metadata;
   std::unique_ptr<DelegatedFrameData> delegated_frame_data;
   std::unique_ptr<GLFrameData> gl_frame_data;
 
-  void AssignTo(CompositorFrame* target);
-
  private:
   DISALLOW_COPY_AND_ASSIGN(CompositorFrame);
 };