Fix reporting of TouchToFirstScroll latency metrics

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 <stdint.h>
 
 #include <memory>
@@ skipping 49 matching lines @@
   // Timestamp when a tab is requested to be shown.
   TAB_SHOW_COMPONENT,
   // Timestamp when the frame is swapped in renderer.
   INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT,
   // Timestamp of when the browser process receives a buffer swap notification
   // from the renderer.
   INPUT_EVENT_BROWSER_RECEIVED_RENDERER_SWAP_COMPONENT,
   // Timestamp of when the gpu service began swap buffers, unlike
   // INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT which measures after.
   INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT,
+  // Timestamp of when the scroll update gesture from a mouse wheel event.

[tdresser, 2016/04/22 17:55:59]

Comment is missing a verb or two.

[dtapuska, 2016/04/22 18:15:00]

Done.

+  INPUT_EVENT_LATENCY_GENERATE_SCROLL_UPDATE_FROM_MOUSE_WHEEL,
   // ---------------------------TERMINAL COMPONENT-----------------------------
   // TERMINAL COMPONENT is when we show the latency end in chrome://tracing.
   // Timestamp when the mouse event is acked from renderer and it does not
   // cause any rendering scheduled.
   INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT,
   // Timestamp when the mouse wheel event is acked from renderer and it does not
   // cause any rendering scheduled.
   INPUT_EVENT_LATENCY_TERMINATED_MOUSE_WHEEL_COMPONENT,
   // Timestamp when the keyboard event is acked from renderer and it does not
   // cause any rendering scheduled.
@@ skipping 10 matching lines @@
   // 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 commit to be scheduled
   // but the commit was aborted since it carried no new information.
   INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT,
   // This component indicates that the input causes a swap to be scheduled
   // but the swap failed.
   INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT,
   LATENCY_COMPONENT_TYPE_LAST =
-    INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT,
+      INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT,
 };
 
 class EVENTS_BASE_EXPORT LatencyInfo {
  public:
   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_t sequence_number;
     // Average time of events that happened in this component.
@@ skipping 123 matching lines @@
   bool terminated_;
 
 #if !defined(OS_IOS)
   friend struct IPC::ParamTraits<ui::LatencyInfo>;
 #endif
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_LATENCY_INFO_H_