[Media] Record time it takes to start rendering audio and video

media/renderers/video_renderer_impl.cc

 // 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.
 
 #include "media/renderers/video_renderer_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 404 matching lines @@
     // prerolling frames before the actual start time that will be dropped.
     if (algorithm_->frames_queued() > 1 || received_end_of_stream_ ||
         frame->timestamp() >= start_timestamp_ || low_delay_ ||
         !video_frame_stream_->CanReadWithoutStalling()) {
       scoped_refptr<VideoFrame> first_frame =
           algorithm_->Render(base::TimeTicks(), base::TimeTicks(), nullptr);
       CheckForMetadataChanges(first_frame->format(),
                               first_frame->natural_size());
       sink_->PaintSingleFrame(first_frame);
       painted_first_frame_ = true;
+      client_->OnFirstFrameRender();
     }
   }
 
   // Signal buffering state if we've met our conditions.
   if (buffering_state_ == BUFFERING_HAVE_NOTHING && HaveEnoughData_Locked())
     TransitionToHaveEnough_Locked();
 
   // Always request more decoded video if we have capacity.
   AttemptRead_Locked();
 }
@@ skipping 275 matching lines @@
 
 void VideoRendererImpl::AttemptReadAndCheckForMetadataChanges(
     VideoPixelFormat pixel_format,
     const gfx::Size& natural_size) {
   base::AutoLock auto_lock(lock_);
   CheckForMetadataChanges(pixel_format, natural_size);
   AttemptRead_Locked();
 }
 
 }  // namespace media