Add UMA histograms for more detailed latency tracking on the CRD host.

remoting/proto/video.proto

 // Copyright (c) 2012 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.
 
 // Protocol for video messages.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
@@ skipping 53 matching lines @@
   // True when |desktop_shape_rects| should be used, false to indicate that
   // the frame is un-shaped. If the shape has not changed since the preceding
   // frame then this field should be omitted.
   optional bool use_desktop_shape = 11;
 
   // Optional frame timestamp. Used in tests to estimate frame latency.
   optional int64 timestamp = 12;
 
   // Frame identifier used to match VideoFrame and VideoAck.
   optional int32 frame_id = 13;
+
+  // Time from when the last event was received until capturing has started.
+  optional int64 capture_pending_time_ms = 14;
+
+  // Total overhead time for IPC and threading when capturing frames.
+  optional int64 capture_overhead_time_ms = 15;
+
+  // Time between when the frame was captured and when encoder started encoding
+  // it.
+  optional int64 encode_pending_time_ms = 16;
+
+  // Time for which the frame is blocked until it's sent to the client.
+  optional int64 send_pending_time_ms = 17;
 }
 
 // VideoAck acknowledges that the frame in the VideoPacket with the same
 // frame_id has been rendered. VideoAck messages must be sent only for frames
 // that have frame_id field set. They must be sent the same order in which
 // the corresponding VideoPackets were received.
 message VideoAck {
   // Frame ID.
   optional int32 frame_id = 1;
 }