Implement MediaMetadata artwork in content

content/browser/media/android/media_web_contents_observer_android.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 "content/browser/media/android/media_web_contents_observer_android.h"
 
 #include "base/memory/ptr_util.h"
 #include "content/browser/media/android/browser_media_player_manager.h"
 #include "content/browser/media/android/browser_media_session_manager.h"
 #include "content/browser/media/android/browser_surface_view_manager.h"
@@ skipping 62 matching lines @@
   auto it = surface_view_managers_.find(render_frame_host);
   if (it != surface_view_managers_.end())
     return it->second;
 
   BrowserSurfaceViewManager* manager =
       new BrowserSurfaceViewManager(render_frame_host);
   surface_view_managers_.set(render_frame_host, base::WrapUnique(manager));
   return manager;
 }
 
+void MediaWebContentsObserverAndroid::SetMediaSessionManagerForTest(
+    RenderFrameHost* render_frame_host, BrowserMediaSessionManager* manager) {

[dcheng, 2016/07/05 02:36:55]

Nit: please pass |manager| through as a std::unique_ptr.

[Zhiqiang Zhang (Slow), 2016/07/05 15:30:30]

Done. Though I think we are putting too much magic code here for test. We need
base::WrapUnique on the call site, and need std::forward in this method since
media_session_managers_.set() uses copy ctor which is removed in
std::unique_ptr.

[dcheng, 2016/07/06 02:34:15]

If a pointer param is transferring ownership, it should be passed a unique_ptr,
regardless of whether or not it's in a test. The tradeoff is a bit more typing
to be explicit about ownership, but it turns out to be quite helpful in seeing
how ownership flows through a system.

+  media_session_managers_.set(render_frame_host, base::WrapUnique(manager));
+}
+
 void MediaWebContentsObserverAndroid::SuspendAllMediaPlayers() {
   web_contents()->ForEachFrame(
       base::Bind(&SuspendAllMediaPlayersInRenderFrame));
 }
 
 bool MediaWebContentsObserverAndroid::RequestPlay(
     RenderFrameHost* render_frame_host,
     int delegate_id,
     bool has_audio,
     bool is_remote,
@@ skipping 184 matching lines @@
     NOTREACHED() << "OnSetCdm: CDM not found for " << cdm_id;
     return;
   }
 
   // TODO(xhwang): This could possibly fail. In that case we should reject the
   // promise.
   media_player->SetCdm(cdm);
 }
 
 }  // namespace content