Report WMPI components memory usage to UMA

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 6e01840d71c6e0e05129c139d91354fd04f2f4d9..4cd83748622fe4fc49b38315bba13aed37223290 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -15,8 +15,10 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
+#include "base/memory/memory_pressure_listener.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/optional.h"
 #include "base/threading/thread.h"
 #include "base/time/default_tick_clock.h"
 #include "base/timer/elapsed_timer.h"
@@ -343,11 +345,16 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   void SetSuspendState(bool is_suspended);
 
   // Called at low frequency to tell external observers how much memory we're
-  // using for video playback.  Called by |memory_usage_reporting_timer_|.
+  // using for video playback.  Called by |memory_usage_reporting_timer_| and
+  // when we get notified about memory pressure via MemoryPressureListener.
   // Memory usage reporting is done in two steps, because |demuxer_| must be
   // accessed on the media thread.
-  void ReportMemoryUsage();
-  void FinishMemoryUsageReport(int64_t demuxer_memory_usage);
+  using OptionalMemoryPressureLevel =
+      base::Optional<base::MemoryPressureListener::MemoryPressureLevel>;
+  void ReportMemoryUsage(OptionalMemoryPressureLevel memory_pressure_level);
+  void FinishMemoryUsageReport(
+      OptionalMemoryPressureLevel memory_pressure_level,
+      int64_t demuxer_memory_usage);
 
   // Called during OnHidden() when we want a suspended player to enter the
   // paused state after some idle timeout.
@@ -358,6 +365,9 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // Returns true if the player is hidden.
   bool IsHidden() const;
 
+  void OnMemoryPressure(
+      base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
+
   blink::WebLocalFrame* frame_;
 
   // The playback state last reported to |delegate_|, to avoid setting duplicate
@@ -579,6 +589,8 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // Whether the player is currently in autoplay muted state.
   bool autoplay_muted_ = false;
 
+  std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
+
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };