WIP: Plumbing input event latency reporting through Mus GPU.

ui/latency/mojo/latency_info.mojom

 // Copyright 2016 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.
 
 module ui.mojom;
 
 import "mojo/common/time.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
 enum LatencyComponentType {
@@ skipping 27 matching lines @@
   INPUT_EVENT_LATENCY_FORWARD_SCROLL_UPDATE_TO_MAIN_COMPONENT,
   // Timestamp when the event's ack is received by the RWH.
   INPUT_EVENT_LATENCY_ACK_RWH_COMPONENT,
   // Frame number when a window snapshot was requested. The snapshot
   // is taken when the rendering results actually reach the screen.
   WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT,
   // 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 display compositor receives a compositor frame.
+  // Display compositor can be either in the browser process or in Mus.
+  DISPLAY_COMPOSITOR_RECEIVED_FRAME_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 gesture scroll update is generated from a mouse wheel
   // event.
   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 event is acked from renderer when it does not
   // cause any rendering to be scheduled.
@@ skipping 41 matching lines @@
 
 // See ui/latency/latency_info.h
 struct LatencyInfo {
   string trace_name;
   array<LatencyComponentPair> latency_components;
   array<gfx.mojom.PointF> input_coordinates;
   int64 trace_id;
   bool coalesced;
   bool terminated;
 };