Implement service-side surface synchronization

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 206a4a050d0d8ddbae3278b721918aeebdd8fe40..296006f73c2614a5ebe6b9c4876c859efdc5c6c0 100644
--- a/cc/output/compositor_frame_metadata.h
+++ b/cc/output/compositor_frame_metadata.h
@@ -78,6 +78,10 @@ class CC_EXPORT CompositorFrameMetadata {
   // This is the set of Surfaces that are referenced by this frame.
   std::vector<SurfaceId> referenced_surfaces;
 
+  // This indicates whether this CompositorFrame can be activated even if
+  // dependencies haven't been resolved.
+  bool can_activate_without_dependencies = true;

[vmpstr, 2017/02/08 19:25:39]

Based on the comment, I think the variable name is ambiguous

"can activate without dependencies" could also mean if there are no
dependencies, this can activate. I don't mind the name, but if there's something
better, then I'd prefer that :P

[rjkroege, 2017/02/08 21:52:29]

how about activation_can_ignore_missing_dependencies

[Fady Samuel, 2017/02/08 23:39:57]

Changed to can_activate_before_dependencies.

[Fady Samuel, 2017/02/08 23:39:57]

I've changed to can_activate_before_dependencies...more or less says the same
thing.

+
  private:
   CompositorFrameMetadata(const CompositorFrameMetadata& other);
   CompositorFrameMetadata operator=(const CompositorFrameMetadata&) = delete;