Send input event's LatencyInfo back from renderer to browser when acked

ui/base/latency_info.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_BASE_LATENCY_INFO_H_
 #define UI_BASE_LATENCY_INFO_H_
 
 #include <map>
 #include <utility>
 
@@ skipping 41 matching lines @@
   typedef std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>
       LatencyMap;
 
   LatencyInfo();
 
   ~LatencyInfo();
 
   // Merges the contents of another LatencyInfo into this one.
   void MergeWith(const LatencyInfo& other);
 
+  // Add LatencyComponents that are in |other| but not in |this|.
+  void AddNewLatencyFrom(const LatencyInfo& other);
+
   // Modifies the current sequence number for a component, and adds a new
   // sequence number with the current timestamp.
   void AddLatencyNumber(LatencyComponentType component,
                         int64 id,
                         int64 component_sequence_number);
 
   // Modifies the current sequence number and adds a certain number of events
   // for a specific component.
   void AddLatencyNumberWithTimestamp(LatencyComponentType component,
                                      int64 id,
@@ skipping 12 matching lines @@
 
   LatencyMap latency_components;
 
   // This represents the final time that a frame is displayed it.
   base::TimeTicks swap_timestamp;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_LATENCY_INFO_H_