Mute audio for Spitzer playbacks that haven't received focus yet.

content/browser/media/android/media_session_controller_unittest.cc

 // Copyright 2016 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 "base/tuple.h"
 #include "content/browser/media/android/media_session.h"
 #include "content/browser/media/android/media_session_controller.h"
 #include "content/browser/media/android/media_web_contents_observer_android.h"
 #include "content/common/media/media_player_delegate_messages.h"
 #include "content/test/test_render_view_host.h"
@@ skipping 128 matching lines @@
   EXPECT_TRUE(media_session()->IsSuspended());
   EXPECT_FALSE(media_session()->IsControllable());
 }
 
 TEST_F(MediaSessionControllerTest, VolumeMultiplier) {
   ASSERT_TRUE(controller_->Initialize(true, false, DurationJustRight()));
   EXPECT_FALSE(media_session()->IsSuspended());
   EXPECT_TRUE(media_session()->IsControllable());
 
   // Upon creation of the MediaSession the default multiplier will be sent.
+  // It's important to verify this since the renderer will mute the stream until
+  // playback focus has been approved.
   EXPECT_TRUE(ReceivedMessageVolumeMultiplierUpdate<
               MediaPlayerDelegateMsg_UpdateVolumeMultiplier>(1.0));
 
   // Verify a different volume multiplier is sent.
   const double kTestMultiplier = 0.5;
   SetVolumeMultiplier(kTestMultiplier);
   EXPECT_TRUE(ReceivedMessageVolumeMultiplierUpdate<
               MediaPlayerDelegateMsg_UpdateVolumeMultiplier>(kTestMultiplier));
 }
 
@@ skipping 48 matching lines @@
   EXPECT_EQ(current_player_id, controller_->get_player_id_for_testing());
 
   // Switch to a remote player, which should release the session.
   ASSERT_TRUE(controller_->Initialize(true, true, DurationJustRight()));
   EXPECT_TRUE(media_session()->IsSuspended());
   EXPECT_FALSE(media_session()->IsControllable());
   EXPECT_EQ(current_player_id, controller_->get_player_id_for_testing());
 }
 
 }  // namespace content