Revert of Letting Flash join MediaSession (stack implementaion)

content/browser/media/session/media_session_browsertest.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 "content/browser/media/session/media_session.h"
 
 #include <stddef.h>
 
 #include <list>
 #include <vector>
@@ skipping 96 matching lines @@
   }
 
   void OnPlayerPaused(MockMediaSessionObserver* media_session_observer,
                       int player_id) {
     media_session_->OnPlayerPaused(media_session_observer, player_id);
   }
 
   bool HasAudioFocus() { return media_session_->IsActiveForTest(); }
 
   content::AudioFocusManager::AudioFocusType GetSessionAudioFocusType() {
-    return media_session_->audio_focus_type();
+    return media_session_->audio_focus_type_for_test();
   }
 
   bool IsControllable() { return media_session_->IsControllable(); }
 
   bool IsSuspended() { return media_session_->IsSuspended(); }
 
   void UIResume() {
     media_session_->Resume(MediaSession::SuspendType::UI);
   }
 
@@ skipping 1210 matching lines @@
                  media::MediaContentType::Persistent);
   clock->Advance(base::TimeDelta::FromMilliseconds(1000));
   media_session_->Stop(MediaSession::SuspendType::UI);
 
   std::unique_ptr<base::HistogramSamples> samples(
       tester.GetHistogramSamplesSinceCreation("Media.Session.ActiveTime"));
   EXPECT_EQ(2, samples->TotalCount());
   EXPECT_EQ(1, samples->GetCount(1000));
   EXPECT_EQ(1, samples->GetCount(10000));
 }