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

cc/output/compositor_frame_metadata.h

Index: cc/output/compositor_frame_metadata.h
diff --git a/cc/output/compositor_frame_metadata.h b/cc/output/compositor_frame_metadata.h
index 2ac6a334d83720cc1cfb5633109136cddedd92bd..c2e13fe6e3fc91b8ec7d64ebfa180376b54143f7 100644
--- a/cc/output/compositor_frame_metadata.h
+++ b/cc/output/compositor_frame_metadata.h
@@ -23,9 +23,13 @@ namespace cc {
 class CC_EXPORT CompositorFrameMetadata {
  public:
   CompositorFrameMetadata();
-  CompositorFrameMetadata(const CompositorFrameMetadata& other);
+  CompositorFrameMetadata(CompositorFrameMetadata&& other);
   ~CompositorFrameMetadata();
 
+  CompositorFrameMetadata& operator=(CompositorFrameMetadata&& other);
+
+  CompositorFrameMetadata Clone() const;
+
   // The device scale factor used to generate this compositor frame.
   float device_scale_factor;
 
@@ -65,6 +69,10 @@ class CC_EXPORT CompositorFrameMetadata {
 
   // This is the set of Surfaces that are referenced by this frame.
   std::vector<SurfaceId> referenced_surfaces;
+
+ private:
+  CompositorFrameMetadata(const CompositorFrameMetadata& other);
+  CompositorFrameMetadata operator=(const CompositorFrameMetadata&) = delete;
 };
 
 }  // namespace cc