De-dupe copy requests for tab capture in DelegatedFrameHost.

content/browser/media/capture/video_capture_oracle.cc

 // Copyright (c) 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/browser/media/capture/video_capture_oracle.h"
 
 #include <algorithm>
 
 #include "base/format_macros.h"
 #include "base/strings/stringprintf.h"
@@ skipping 102 matching lines @@
 int VideoCaptureOracle::RecordCapture() {
   smoothing_sampler_.RecordSample();
   content_sampler_.RecordSample(GetFrameTimestamp(frame_number_));
   return frame_number_++;
 }
 
 bool VideoCaptureOracle::CompleteCapture(int frame_number,
                                          base::TimeTicks* frame_timestamp) {
   // Drop frame if previous frame number is higher.
   if (last_delivered_frame_number_ > frame_number) {
-    LOG(WARNING) << "Out of order frame delivery detected.  Dropping frame.";
+    LOG(WARNING) << "Out of order frame delivery detected (have #"
+                 << frame_number << ", last was #"
+                 << last_delivered_frame_number_ << ").  Dropping frame.";
     return false;
   }
   last_delivered_frame_number_ = frame_number;
 
   *frame_timestamp = GetFrameTimestamp(frame_number);
 
   // If enabled, log a measurement of how this frame timestamp has incremented
   // in relation to an ideal increment.
   if (VLOG_IS_ON(2) && frame_number > 0) {
     const base::TimeDelta delta =
@@ skipping 284 matching lines @@
   if (borrowed_time_ >= min_capture_period_) {
     borrowed_time_ -= min_capture_period_;
     frame_timestamp_ = base::TimeTicks();
   } else {
     sequence_offset_ += advancement;
     frame_timestamp_ = timebase + sequence_offset_;
   }
 }
 
 }  // namespace content