Media Remoting: Switch to remoting only when media is playing.

media/remoting/remoting_renderer_controller.cc

 // 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.
 
 #include "media/remoting/remoting_renderer_controller.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/threading/thread_checker.h"
 #include "media/remoting/remoting_cdm_context.h"
@@ skipping 186 matching lines @@
     case AudioCodec::kCodecALAC:
     case AudioCodec::kCodecAC3:
       return true;
     default:
       VLOG(2) << "Remoting does not support audio codec: "
               << audio_decoder_config_.codec();
       return false;
   }
 }
 
+void RemotingRendererController::OnPlaying() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  is_paused_ = false;
+  UpdateAndMaybeSwitch();
+}
+
+void RemotingRendererController::OnPaused() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  is_paused_ = true;
+}
+
 bool RemotingRendererController::ShouldBeRemoting() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (switch_renderer_cb_.is_null())
     return false;  // No way to switch to a RemotingRenderImpl.
 
   const RemotingSessionState state = remoting_source_->state();
   if (is_encrypted_) {
     // Due to technical limitations when playing encrypted content, once a
     // remoting session has been started, always return true here to indicate
@@ skipping 41 matching lines @@
 }
 
 void RemotingRendererController::UpdateAndMaybeSwitch() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   bool should_be_remoting = ShouldBeRemoting();
 
   if (remote_rendering_started_ == should_be_remoting)
     return;
 
+  if (should_be_remoting && is_paused_)

[miu, 2016/12/19 22:56:53]

Let's add a comment to explain why this is good for the user experience.

[xjz, 2016/12/20 00:12:36]

Done.

+    return;  // Only switches to remoting when media is playing.

[miu, 2016/12/19 22:56:53]

s/switches/switch/

[xjz, 2016/12/20 00:12:36]

Done.

+
   // Switch between local renderer and remoting renderer.
   remote_rendering_started_ = should_be_remoting;
 
   if (remote_rendering_started_) {
     DCHECK(!switch_renderer_cb_.is_null());
     if (remoting_source_->state() ==
         RemotingSessionState::SESSION_PERMANENTLY_STOPPED) {
       switch_renderer_cb_.Run();
       return;
     }
     // |switch_renderer_cb_.Run()| will be called after remoting is started
     // successfully.
     remoting_source_->StartRemoting(this);
   } else {
     // For encrypted content, it's only valid to switch to remoting renderer,
     // and never back to the local renderer. The RemotingCdmController will
     // force-stop the session when remoting has ended; so no need to call
     // StopRemoting() from here.
     DCHECK(!is_encrypted_);
     switch_renderer_cb_.Run();
     remoting_source_->StopRemoting(this);
   }
 }
 
 }  // namespace media