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

cc/output/compositor_frame_metadata.cc

Index: cc/output/compositor_frame_metadata.cc
diff --git a/cc/output/compositor_frame_metadata.cc b/cc/output/compositor_frame_metadata.cc
index d77cca006d54508a2a13274973fea426413659ca..a98eee270f33bc7f2ed6f6d017a572c4249189d9 100644
--- a/cc/output/compositor_frame_metadata.cc
+++ b/cc/output/compositor_frame_metadata.cc
@@ -16,9 +16,20 @@ CompositorFrameMetadata::CompositorFrameMetadata()
       root_background_color(SK_ColorWHITE) {}
 
 CompositorFrameMetadata::CompositorFrameMetadata(
-    const CompositorFrameMetadata& other) = default;
+    CompositorFrameMetadata&& other) = default;
 
 CompositorFrameMetadata::~CompositorFrameMetadata() {
 }
 
+CompositorFrameMetadata& CompositorFrameMetadata::operator=(
+    CompositorFrameMetadata&& other) = default;
+
+CompositorFrameMetadata CompositorFrameMetadata::Clone() const {
+  CompositorFrameMetadata metadata(*this);
+  return metadata;
+}
+
+CompositorFrameMetadata::CompositorFrameMetadata(
+    const CompositorFrameMetadata& other) = default;
+
 }  // namespace cc