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

content/common/browser_rendering_stats.cc

Index: content/common/browser_rendering_stats.cc
diff --git a/content/common/browser_rendering_stats.cc b/content/common/browser_rendering_stats.cc
index 0ead3c7f067255912f42f93de6d70acea8d57073..9c0c8259de5e53c262bd66dc27b0244d511de2ba 100644
--- a/content/common/browser_rendering_stats.cc
+++ b/content/common/browser_rendering_stats.cc
@@ -9,7 +9,8 @@ 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() {}
@@ -26,6 +27,10 @@ void BrowserRenderingStats::EnumerateFields(
   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