WIP - WebMediaPlayer switch media renderer.

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 0b76251098e5f95c5021d7f3586a3a9f60e17ea1..2dba1773b8594bc6466e91ca45b0e80c88c848b3 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -207,7 +207,11 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
       surface_manager_(params.surface_manager()),
       overlay_surface_id_(SurfaceManager::kNoSurfaceID),
       suppress_destruction_errors_(false),
-      can_suspend_state_(CanSuspendState::UNKNOWN) {
+      can_suspend_state_(CanSuspendState::UNKNOWN),
+      is_media_remoting_(false),
+      is_remote_sink_available_(false),
+      is_encrypted_content_(false),
+      is_remote_cdm_cb_(params.is_remote_cdm_cb()) {
   DCHECK(!adjust_allocated_memory_cb_.is_null());
   DCHECK(renderer_factory_);
   DCHECK(client_);
@@ -311,11 +315,13 @@ void WebMediaPlayerImpl::DisableOverlay() {
 void WebMediaPlayerImpl::enteredFullscreen() {
   if (!force_video_overlays_)
     EnableOverlay();
+  videoEnteredFullscreen();
 }
 
 void WebMediaPlayerImpl::exitedFullscreen() {
   if (!force_video_overlays_)
     DisableOverlay();
+  videoExitedFullscreen();
 }
 
 void WebMediaPlayerImpl::DoLoad(LoadType load_type,
@@ -864,6 +870,16 @@ void WebMediaPlayerImpl::OnEncryptedMediaInitData(
   // TODO(xhwang): Update this UMA name. https://crbug.com/589251
   UMA_HISTOGRAM_COUNTS("Media.EME.NeedKey", 1);
 
+  is_encrypted_content_ = true;
+  // Check whether we can switch to remoting for encrypted video. Once switching
+  // happens, it is not able to switch back to local media renderer without
+  // refreshing the page.
+  if (is_remote_sink_available_ && !is_media_remoting_ &&
+      !is_remote_cdm_cb_.is_null() && is_remote_cdm_cb_.Run()) {
+    is_media_remoting_ = true;
+    SwitchMediaRenderer();
+  }
+
   encrypted_client_->encrypted(
       ConvertToWebInitDataType(init_data_type), init_data.data(),
       base::saturated_cast<unsigned int>(init_data.size()));
@@ -1725,4 +1741,45 @@ void WebMediaPlayerImpl::ScheduleIdlePauseTimer() {
                                 this, &WebMediaPlayerImpl::OnPause);
 }
 
+void WebMediaPlayerImpl::videoEnteredFullscreen() {
+  if (is_encrypted_content_ || is_media_remoting_ || !is_remote_sink_available_)
+    return;
+
+  is_media_remoting_ = true;
+  SwitchMediaRenderer();
+}
+
+void WebMediaPlayerImpl::videoExitedFullscreen() {
+  if (is_encrypted_content_ || !is_media_remoting_)
+    return;
+
+  is_media_remoting_ = false;
+  SwitchMediaRenderer();
+}
+
+void WebMediaPlayerImpl::OnSinkAvailable() {

[liberato (no reviews please), 2016/08/29 16:49:12]

would it be clearer if these things were pulled out into another class?

for example, could wmpi check someNewCastStateThing_.IsMediaRemoting()?  it
could chain calls to videoEnteredFullscreen over to someNewCastStateThing, too. 
OnSink* could be moved over.

it might make things more cumbersome, but it depends a lot on how much code is
going to be added.  it also depends on where the callbacks are set up, etc.

not sure if it would make things clearer, or just end up with a bunch of chained
methods from wmpi => new thing without really removing much code.

[xjz, 2016/09/09 23:13:06]

Yes. Done. 

+  is_remote_sink_available_ = true;
+}
+
+void WebMediaPlayerImpl::OnSinkGone() {
+  is_remote_sink_available_ = false;
+  if (is_media_remoting_) {
+    is_media_remoting_ = false;
+    if (!is_encrypted_content_) {
+      SwitchMediaRenderer();
+    } else {
+      // TODO(xjz): Need to tell the user to refresh the page.
+    }
+  }
+}
+
+// Switch media renderer between local playing back and remoting media renderer

[liberato (no reviews please), 2016/08/29 16:49:12]

please move this to the .h (good comment, by the way).

[xjz, 2016/09/09 23:13:06]

Done.

+// according to |is_media_remoting_|.
+// Note: Always set |is_media_remoting_| accordingly before calling this method.
+void WebMediaPlayerImpl::SwitchMediaRenderer() {

[liberato (no reviews please), 2016/08/29 16:49:12]

maybe take the new value of is_media_remoting_ as an argument, and have it take
responsibility for setting it.

[xjz, 2016/09/09 23:13:06]

Done.

+  VLOG(2) << "Switch to: " << (is_media_remoting_ ? "Remoting" : "Local");
+  pipeline_controller_.Suspend();
+  pipeline_controller_.Resume();

[liberato (no reviews please), 2016/08/29 16:49:12]

how does this switch to remote playback?

is there there logic going to go into CreateRenderer to check
is_media_remoting_?

[xjz, 2016/09/09 23:13:06]

Yes. The implementation will be in the upcoming CL. Added comment for this.

+}
+
 }  // namespace media