cc: Add a Scheduling.SwapAckWasFast UMA.

cc/scheduler/compositor_timing_history.h

 // Copyright 2014 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 CC_SCHEDULER_COMPOSITOR_TIMING_HISTORY_H_
 #define CC_SCHEDULER_COMPOSITOR_TIMING_HISTORY_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 99 matching lines @@
   base::TimeTicks begin_main_frame_sent_time_;
   base::TimeTicks begin_main_frame_start_time_;
   base::TimeTicks begin_main_frame_end_time_;
   base::TimeTicks pending_tree_main_frame_time_;
   base::TimeTicks prepare_tiles_start_time_;
   base::TimeTicks activate_start_time_;
   base::TimeTicks active_tree_main_frame_time_;
   base::TimeTicks draw_start_time_;
   base::TimeTicks swap_start_time_;
 
+  // Watchdog timers.
+  bool swap_ack_watchdog_enabled_;
+  int swap_ack_watchdog_begin_impl_frame_count_;
+
   std::unique_ptr<UMAReporter> uma_reporter_;
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CompositorTimingHistory);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_COMPOSITOR_TIMING_HISTORY_H_