Use validating IPC enum macros in common param traits.

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>
@@ skipping 47 matching lines @@
   INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT,
   // This component indicates that the input causes a commit to be scheduled
   // but the commit failed.
   INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT,
   // This component indicates that the input causes a swap to be scheduled
   // but the swap failed.
   INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT,
   // This component indicates that the cached LatencyInfo number exceeds the
   // maximal allowed size.
   LATENCY_INFO_LIST_TERMINATED_OVERFLOW_COMPONENT,
+  LATENCY_COMPONENT_TYPE_LAST = LATENCY_INFO_LIST_TERMINATED_OVERFLOW_COMPONENT
 };
 
 struct EVENTS_BASE_EXPORT LatencyInfo {
   struct LatencyComponent {
     // Nondecreasing number that can be used to determine what events happened
     // in the component at the time this struct was sent on to the next
     // component.
     int64 sequence_number;
     // Average time of events that happened in this component.
     base::TimeTicks event_time;
@@ skipping 57 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_