Provide a WebContents API to discover the playback of a fullscreen video.

content/renderer/media/webmediaplayer_ms_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "content/public/renderer/media_stream_renderer_factory.h"
 #include "content/renderer/media/webmediaplayer_ms.h"
@@ skipping 76 matching lines @@
 
   void ClearStaleFlag(int delegate_id) override {
     EXPECT_EQ(delegate_id_, delegate_id);
   }
 
   bool IsStale(int delegate_id) override {
     EXPECT_EQ(delegate_id_, delegate_id);
     return false;
   }
 
+  void SetIsFullscreen(int delegate_id, bool is_fullscreen) override {
+    EXPECT_EQ(delegate_id_, delegate_id);
+  }
+
   bool IsFrameHidden() override { return is_hidden_; }
   bool IsFrameClosed() override { return false; }
   bool IsBackgroundVideoPlaybackUnlocked() override { return false; }
 
   void set_hidden(bool is_hidden) { is_hidden_ = is_hidden; }
 
  private:
   int delegate_id_ = 1234;
   Observer* observer_ = nullptr;
   bool playing_ = false;
@@ skipping 850 matching lines @@
   // OnShown() should restart after a forced suspension.
   player_->OnFrameShown();
   EXPECT_FALSE(player_->paused());
   EXPECT_CALL(*this, DoSetWebLayer(false));
 
   base::RunLoop().RunUntilIdle();
 }
 #endif
 
 }  // namespace content