Android MediaSession: do not resume a UI suspended session on a system resume.

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 2012 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/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 3298 matching lines @@
 #if defined(OS_ANDROID)
 
 void WebContentsImpl::OnMediaSessionStateChanged() {
   MediaSession* session = MediaSession::Get(this);
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     MediaSessionStateChanged(session->IsControllable(),
                                              session->IsSuspended()));
 }
 
 void WebContentsImpl::ResumeMediaSession() {
-  MediaSession::Get(this)->Resume();
+  MediaSession::Get(this)->Resume(MediaSession::SuspendType::UI);

[whywhat, 2015/07/21 19:21:28]

Perhaps you could pass the SuspendType::UI from Resume() and Suspend() and
SuspendType::System from OnResume/OnSuspend to avoid changing the MediaSession's
public API.

 }
 
 void WebContentsImpl::SuspendMediaSession() {
-  MediaSession::Get(this)->Suspend();
+  MediaSession::Get(this)->Suspend(MediaSession::SuspendType::UI);
 }
 
 #endif  // defined(OS_ANDROID)
 
 void WebContentsImpl::OnFirstVisuallyNonEmptyPaint() {
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     DidFirstVisuallyNonEmptyPaint());
 
   did_first_visually_non_empty_paint_ = true;
 
@@ skipping 1189 matching lines @@
   player_map->erase(it);
 }
 
 void WebContentsImpl::SetForceDisableOverscrollContent(bool force_disable) {
   force_disable_overscroll_content_ = force_disable;
   if (view_)
     view_->SetOverscrollControllerEnabled(CanOverscrollContent());
 }
 
 }  // namespace content