[Cleanup] Rename Hidden to Background in WMPI.

media/blink/webmediaplayer_impl.h

Index: media/blink/webmediaplayer_impl.h
diff --git a/media/blink/webmediaplayer_impl.h b/media/blink/webmediaplayer_impl.h
index 0942929e41b86d6a6792022928d4d7d14af1323c..08e70b736b9dd40a513add59eb0c470349af7e53 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -329,7 +329,7 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // are:
   //   - isRemote(),
   //   - hasVideo(),
-  //   - delegate_->IsHidden(),
+  //   - delegate_->IsFrameHidden(),
   //   - network_state_, ready_state_,
   //   - is_idle_, must_suspend_,
   //   - paused_, ended_,
@@ -352,7 +352,7 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   void ReportMemoryUsage();
   void FinishMemoryUsageReport(int64_t demuxer_memory_usage);
 
-  // Called during OnHidden() when we want a suspended player to enter the
+  // Called during OnFrameHidden() when we want a suspended player to enter the
   // paused state after some idle timeout.
   void ScheduleIdlePauseTimer();
 
@@ -367,8 +367,8 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
 
   void CreateWatchTimeReporter();
 
-  // Returns true if the player is hidden.
-  bool IsHidden() const;
+  // Returns true if the player is in the background.
+  bool IsBackgrounded() const;
 
   // Returns true if the player's source is streaming.
   bool IsStreaming() const;
@@ -377,17 +377,17 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // is intended for android.
   bool DoesOverlaySupportMetadata() const;
 
-  // Whether the video should be paused when hidden. Uses metadata so has
-  // meaning only after the pipeline has started, otherwise returns false.
+  // Whether the video should be paused when in the background. Uses metadata so
+  // has meaning only after the pipeline has started, otherwise returns false.
   // Doesn't check if the video can actually be paused depending on the
   // pipeline's state.
-  bool ShouldPauseVideoWhenHidden() const;
+  bool ShouldPauseVideoWhenBackground() const;
 
-  // Whether the video track should be disabled when hidden. Uses metadata so
-  // has meaning only after the pipeline has started, otherwise returns false.
-  // Doesn't check if the video track can actually be disabled depending on the
-  // pipeline's state.
-  bool ShouldDisableVideoWhenHidden() const;
+  // Whether the video track should be disabled when in the background. Uses
+  // metadata so has meaning only after the pipeline has started, otherwise
+  // returns false. Doesn't check if the video track can actually be disabled
+  // depending on the pipeline's state.
+  bool ShouldDisableVideoWhenBackground() const;
 
   // Whether the video is suitable for background playback optimizations (either
   // pausing it or disabling the video track). Uses metadata so has meaning only
@@ -401,26 +401,27 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // needs to be called to update the optimization state.
   void UpdateBackgroundVideoOptimizationState();
 
-  // Pauses a hidden video only player to save power if possible.
+  // Pauses a background video only player to save power if possible.
   // Must be called when either of the following happens:
-  // - right after the video was hidden,
-  // - right ater the pipeline has resumed if the video is hidden.
+  // - right after the video was backgrounded,
+  // - right ater the pipeline has resumed if the video is in the background.
   void PauseVideoIfNeeded();
 
   // Disables the video track to save power if possible.
   // Must be called when either of the following happens:
-  // - right after the video was hidden,
+  // - right after the video was backgrounded,
   // - right after the pipeline has started (|seeking_| is used to detect the
-  //   when pipeline started) if the video is hidden,
-  // - right ater the pipeline has resumed if the video is hidden.
+  //   when pipeline started) if the video is in the background,
+  // - right ater the pipeline has resumed if the video is in the background.
   void DisableVideoTrackIfNeeded();
 
   // Enables the video track if it was disabled before to save power.
   // Must be called when either of the following happens:
-  // - right after the video was shown,
+  // - right after the video was put in the foreground,
   // - right before the pipeline is requested to resume
   //   (see https://crbug.com/678374),
-  // - right after the pipeline has resumed if the video is not hidden.
+  // - right after the pipeline has resumed if the video is not in the
+  //   background.
   void EnableVideoTrackIfNeeded();
 
   // Overrides the pipeline statistics returned by GetPiplineStatistics() for
@@ -499,9 +500,9 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   bool paused_;
   base::TimeDelta paused_time_;
 
-  // Set if paused automatically when hidden and need to resume when visible.
-  // Reset if paused for any other reason.
-  bool paused_when_hidden_;
+  // Set if paused automatically when backgrounded and need to resume when
+  // foregrounded. Reset if paused for any other reason.
+  bool paused_when_background_;
 
   // Set when starting, seeking, and resuming (all of which require a Pipeline
   // seek). |seek_time_| is only valid when |seeking_| is true.