Allow suspension prior to reaching kHaveFutureData.

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 cde7e38e0a693f2e56086525005bb4e2d23efc8e..d371b832bc066978e25ec26a040657e587e182e5 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -227,7 +227,8 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
       suppress_destruction_errors_(false),
       can_suspend_state_(CanSuspendState::UNKNOWN),
       is_encrypted_(false),
-      underflow_count_(0) {
+      underflow_count_(0),
+      is_client_paused_(true) {
   DCHECK(!adjust_allocated_memory_cb_.is_null());
   DCHECK(renderer_factory_);
   DCHECK(client_);
@@ -589,6 +590,13 @@ void WebMediaPlayerImpl::setBufferingStrategy(
     data_source_->SetBufferingStrategy(buffering_strategy_);
 }
 
+void WebMediaPlayerImpl::setPaused(bool is_paused) {
+  is_client_paused_ = is_paused;
+  if (highest_ready_state_ >= WebMediaPlayer::ReadyStateHaveFutureData)
+    DCHECK_EQ(is_paused, paused_);
+  UpdatePlayState();
+}
+
 bool WebMediaPlayerImpl::hasVideo() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
@@ -1655,6 +1663,11 @@ WebMediaPlayerImpl::UpdatePlayState_ComputePlayState(bool is_remote,
   bool have_future_data =
       highest_ready_state_ >= WebMediaPlayer::ReadyStateHaveFutureData;
 
+  // Once we reach HaveFutureData, our internal paused state should be accurate,
+  // due to ordering of calls we may temporarily be out of sync though. During
+  // that period, we'll retain the most accurate |paused_| state.

[sandersd (OOO until July 31), 2016/08/30 22:41:41]

Is it actually 'most accurate'? It happens to be correct in the path you added,
but it's not necessarily so by contract. (There is a similar situation for
'ended', I opted to actually describe HTMLMediaElement's behavior inside of
WMPI.)

[DaleCurtis, 2016/08/30 22:59:43]

Reworded.

+  bool is_paused = have_future_data ? paused_ : is_client_paused_;
+
   // Background suspend is not enabled for audio-only players unless paused,
   // though in the case of audio-only the session should be kept.
   // Videos are not suspended if the user resumed the playback via the remote
@@ -1666,10 +1679,7 @@ WebMediaPlayerImpl::UpdatePlayState_ComputePlayState(bool is_remote,
       delegate_ && delegate_->IsPlayingBackgroundVideo();
   bool background_suspended = is_backgrounded_video &&
                               !(can_play_backgrounded && is_background_playing);
-
-  // The |paused_| state is not reliable until we |have_future_data|.
-  bool background_pause_suspended =
-      is_backgrounded && have_future_data && paused_;
+  bool background_pause_suspended = is_backgrounded && is_paused;
 
   // Idle suspend is enabled once there is future data. We don't want to idle
   // suspend before that because play() may never be triggered to leave the idle
@@ -1679,16 +1689,15 @@ WebMediaPlayerImpl::UpdatePlayState_ComputePlayState(bool is_remote,
   //
   // TODO(sandersd): Make the delegate suspend idle players immediately when
   // hidden.
-  // TODO(sandersd): If Blink told us the paused state sooner, we could
-  // idle suspend sooner.
-  bool idle_suspended = is_idle_ && have_future_data;
+  bool idle_suspended = is_idle_ && is_paused;
+
+  // If we're already suspended, see if we can wait for user interaction.
+  bool can_stay_suspended = is_suspended && is_paused && !seeking_;
 
   // Combined suspend state.
-  result.is_suspended =
-      is_remote || must_suspend_ || idle_suspended || background_suspended ||
-      background_pause_suspended ||
-      // If we're already suspended, see if we can wait for user interaction.
-      (is_suspended && have_future_data && paused_ && !seeking_);
+  result.is_suspended = is_remote || must_suspend_ || idle_suspended ||
+                        background_suspended || background_pause_suspended ||
+                        can_stay_suspended;
 
   // We do not treat |playback_rate_| == 0 as paused. For the media session,
   // being paused implies displaying a play button, which is incorrect in this