Implement MediaMetadata artwork in content

content/browser/media/android/media_web_contents_observer_android.cc

Index: content/browser/media/android/media_web_contents_observer_android.cc
diff --git a/content/browser/media/android/media_web_contents_observer_android.cc b/content/browser/media/android/media_web_contents_observer_android.cc
index 5a6c451f13a4a9c0a14900372580293ec1b2c368..39125635741638f9e614025bd7f03f2d00607c50 100644
--- a/content/browser/media/android/media_web_contents_observer_android.cc
+++ b/content/browser/media/android/media_web_contents_observer_android.cc
@@ -4,6 +4,8 @@
 
 #include "content/browser/media/android/media_web_contents_observer_android.h"
 
+#include <utility>
+
 #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"
@@ -80,6 +82,12 @@ MediaWebContentsObserverAndroid::GetSurfaceViewManager(
   return manager;
 }
 
+void MediaWebContentsObserverAndroid::SetMediaSessionManagerForTest(
+    RenderFrameHost* render_frame_host,
+    std::unique_ptr<BrowserMediaSessionManager> manager) {
+  media_session_managers_.set(render_frame_host, std::move(manager));
+}
+
 void MediaWebContentsObserverAndroid::SuspendAllMediaPlayers() {
   web_contents()->ForEachFrame(
       base::Bind(&SuspendAllMediaPlayersInRenderFrame));