cc: Add frame timing request plumbing through the layers.

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 017df68429956cc0065a7b98c9a4a7e713f24979..4cef11f97deae35375c594f55e7ab2f5c70c7a83 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -7,6 +7,7 @@
 
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
@@ -17,6 +18,7 @@
 #include "cc/base/cc_export.h"
 #include "cc/base/region.h"
 #include "cc/base/scoped_ptr_vector.h"
+#include "cc/debug/frame_timing_request.h"
 #include "cc/debug/micro_benchmark.h"
 #include "cc/layers/draw_properties.h"
 #include "cc/layers/layer_lists.h"
@@ -505,6 +507,9 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
     return has_render_surface_;
   }
 
+  // Sets new frame timing requests for this layer.
+  void PassFrameTimingRequests(std::vector<FrameTimingRequest>* requests);

[danakj, 2015/01/23 19:15:37]

Sorry I like the Pass on the layerimpl but I'm not so sure about it on the
public API. It seems a bit more fickle to expose it this way, and I think I
prefer a Set method on this class.

[vmpstr, 2015/01/23 19:35:27]

Done.

+
  protected:
   friend class LayerImpl;
   friend class TreeSynchronizer;
@@ -697,6 +702,10 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   scoped_ptr<RenderSurface> render_surface_;
 
   gfx::Rect visible_rect_from_property_trees_;
+
+  std::vector<FrameTimingRequest> frame_timing_requests_;
+  bool frame_timing_requests_dirty_;
+
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };