Wrap MediaMetadata in base::Optional in content and chrome

content/public/browser/web_contents_observer.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "base/process/kill.h"
 #include "base/process/process_handle.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/common/frame_navigate_params.h"
-#include "content/public/common/media_metadata.h"
 #include "content/public/common/resource_type.h"
 #include "content/public/common/security_style.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/page_transition_types.h"
 #include "ui/base/window_open_disposition.h"
 
+namespace base {
+template <typename T> class Optional;
+}  // namespace base
+
 namespace content {
 
 class NavigationEntry;
 class NavigationHandle;
 class RenderFrameHost;
 class RenderViewHost;
 class RenderWidgetHost;
 class WebContents;
 class WebContentsImpl;
 struct AXEventNotificationDetails;
 struct AXLocationChangeNotificationDetails;
 struct FaviconURL;
 struct FrameNavigateParams;
 struct LoadCommittedDetails;
+struct MediaMetadata;
 struct Referrer;
 struct ResourceRedirectDetails;
 struct ResourceRequestDetails;
 struct SecurityStyleExplanations;
 
 // An observer API implemented by classes which are interested in various page
 // load events from WebContents.  They also get a chance to filter IPC messages.
 //
 // Since a WebContents can be a delegate to almost arbitrarily many
 // RenderViewHosts, it is important to check in those WebContentsObserver
@@ skipping 412 matching lines @@
   // Invoked when media is playing or paused.  |id| is unique per player and per
   // RenderFrameHost.  There may be multiple players within a RenderFrameHost
   // and subsequently within a WebContents.  MediaStartedPlaying() will always
   // be followed by MediaStoppedPlaying() after player teardown.  Observers must
   // release all stored copies of |id| when MediaStoppedPlaying() is received.
   using MediaPlayerId = std::pair<RenderFrameHost*, int>;
   virtual void MediaStartedPlaying(const MediaPlayerId& id) {}
   virtual void MediaStoppedPlaying(const MediaPlayerId& id) {}
 
   // Invoked when media session has changed its state.
-  virtual void MediaSessionStateChanged(bool is_controllable,
-                                        bool is_suspended,
-                                        const MediaMetadata& metadata) {}
+  virtual void MediaSessionStateChanged(
+      bool is_controllable,
+      bool is_suspended,
+      const base::Optional<MediaMetadata>& metadata) {}
 
   // Invoked when the renderer process changes the page scale factor.
   virtual void OnPageScaleFactorChanged(float page_scale_factor) {}
 
   // Invoked if an IPC message is coming from a specific RenderFrameHost.
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  RenderFrameHost* render_frame_host);
 
   // Notification that |contents| has gained focus.
   virtual void OnWebContentsFocused() {}
@@ skipping 28 matching lines @@
   void ResetWebContents();
 
   WebContentsImpl* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_