Add compositor support for the LatencyInfo.

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index 629945ecf77bbfc734ccda1090279b7537002f09..a6d1842b9c51e053ede740f74de8c0bff557dc7f 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -18,6 +18,7 @@
 #include "cc/animation/animation_events.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/scoped_ptr_vector.h"
+#include "cc/debug/latency_info.h"
 #include "cc/layers/layer_lists.h"
 #include "cc/output/output_surface.h"
 #include "cc/scheduler/rate_limiter.h"
@@ -211,6 +212,7 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
   void ApplyScrollAndScale(const ScrollAndScaleSet& info);
 
   void SetImplTransform(const gfx::Transform& transform);
+  void SetLatencyInfo(const LatencyInfo& latency_info);
 
   void StartRateLimiter(WebKit::WebGraphicsContext3D* context3d);
   void StopRateLimiter(WebKit::WebGraphicsContext3D* context3d);
@@ -339,6 +341,8 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   bool in_paint_layer_contents_;
 
+  LatencyInfo latency_info_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };