Add UMA/Telemetry stats for end-to-end scroll latency

content/common/browser_rendering_stats.cc

 // 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.
 
 #include "content/common/browser_rendering_stats.h"
 
 namespace content {
 
 BrowserRenderingStats::BrowserRenderingStats() :
     input_event_count(0),
     touch_ui_count(0),
-    touch_acked_count(0) {
+    touch_acked_count(0),
+    scroll_update_count(0) {
 }
 
 BrowserRenderingStats::~BrowserRenderingStats() {}
 
 void BrowserRenderingStats::EnumerateFields(
     cc::RenderingStats::Enumerator* enumerator) const {
   enumerator->AddInt("inputEventCount", input_event_count);
   enumerator->AddTimeDeltaInSecondsF("totalInputLatency", total_input_latency);
 
   enumerator->AddInt("touchUICount", touch_ui_count);
   enumerator->AddTimeDeltaInSecondsF("totalTouchUILatency",
                                      total_touch_ui_latency);
 
   enumerator->AddInt("touchAckedCount", touch_acked_count);
   enumerator->AddTimeDeltaInSecondsF("totalTouchAckedLatency",
                                      total_touch_acked_latency);
+
+  enumerator->AddInt("scrollUpdateCount", scroll_update_count);
+  enumerator->AddTimeDeltaInSecondsF("totalScrollUpdateLatency",
+                                     total_scroll_update_latency);
 }
 
 }  // namespace content