Remove gpu side LatencyInfo merging

ui/events/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_EVENTS_LATENCY_INFO_H_
 #define UI_EVENTS_LATENCY_INFO_H_
 
 #include <map>
 #include <utility>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/time/time.h"
 #include "ui/events/events_base_export.h"
 
 namespace ui {
 
 enum LatencyComponentType {
   // ---------------------------BEGIN COMPONENT-------------------------------
   // BEGIN COMPONENT is when we show the latency begin in chrome://tracing.
@@ skipping 60 matching lines @@
 
   // Map a Latency Component (with a component-specific int64 id) to a
   // component info.
   typedef std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>
       LatencyMap;
 
   LatencyInfo();
 
   ~LatencyInfo();
 
+  // Returns true if the vector |latency_info| is valid. Returns false
+  // if it is not valid and log the |referring_msg|.
+  // This function is mainly used to check the latency_info vector that
+  // is passed between processes using IPC message has reasonable size
+  // so that we are confident the IPC message is not corrupted/compromised.
+  // This check will go away once the IPC system has better built-in scheme
+  // for corruption/compromise detection.
+  static bool Verify(const std::vector<LatencyInfo>& latency_info,
+                     const char* referring_msg);
+
   // 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,
@@ skipping 26 matching lines @@
   LatencyMap latency_components;
   // The unique id for matching the ASYNC_BEGIN/END trace event.
   int64 trace_id;
   // Whether a terminal component has been added.
   bool terminated;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_LATENCY_INFO_H_