[Video] Only start tracking foreground time if the video was resumed.

media/blink/video_frame_compositor.h

Index: media/blink/video_frame_compositor.h
diff --git a/media/blink/video_frame_compositor.h b/media/blink/video_frame_compositor.h
index 03fb4c5d489f5926b264645fb4ab342c3e247a28..ab70cc1637b35eb344a00d25c744b7f6b88225d2 100644
--- a/media/blink/video_frame_compositor.h
+++ b/media/blink/video_frame_compositor.h
@@ -10,6 +10,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/optional.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/time/tick_clock.h"
@@ -103,10 +104,15 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
   // PaintSingleFrame() is not also called while stopped.)
   base::TimeDelta GetCurrentFrameTimestamp() const;
 
-  // Called when the media player is brought to the foreground.
+  // Enumerates the ways background video could be optimized.
+  enum class BackgroundVideoOptimization { Paused, DisabledTrack };
+
+  // Called when the media player is brought to the foreground and was or could
+  // be optimized when in the background.
   // Used to record the time it takes to process the first frame after that.
   // Must be called on the compositor thread.
-  void SetForegroundTime(base::TimeTicks when);
+  void SetForegroundTime(base::TimeTicks when,
+                         BackgroundVideoOptimization optimization);
 
   void set_tick_clock_for_testing(std::unique_ptr<base::TickClock> tick_clock) {
     tick_clock_ = std::move(tick_clock);
@@ -163,6 +169,7 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
   base::TimeDelta last_interval_;
   base::TimeTicks last_background_render_;
   base::TimeTicks foreground_time_;
+  base::Optional<BackgroundVideoOptimization> background_video_optimization_;
 
   // These values are set on the compositor thread, but also read on the media
   // thread when the VFC is stopped.