[Android,Cast] Report correctly when devices are not available.

chrome/browser/media/android/router/media_router_dialog_controller_android.h

 // Copyright 2015 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 CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_
 #define CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_
 
 #include <jni.h>
 
 #include <memory>
@@ skipping 25 matching lines @@
                       const base::android::JavaParamRef<jstring>& jsink_id);
   // Notifies the controller that user chose to close the route.
   void OnRouteClosed(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
       const base::android::JavaParamRef<jstring>& jmedia_route_id);
   // Notifies the controller that the dialog has been closed without the user
   // taking any action (e.g. closing the route or selecting a sink).
   void OnDialogCancelled(JNIEnv* env,
                          const base::android::JavaParamRef<jobject>& obj);
+  // Notifies the controller the media source URN is not supported so it could
+  // properly reject the request.
+  void OnMediaSourceNotSupported(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
  private:
   friend class content::WebContentsUserData<MediaRouterDialogControllerAndroid>;
 
   // Use MediaRouterDialogControllerAndroid::CreateForWebContents() to create an
   // instance.
   explicit MediaRouterDialogControllerAndroid(
       content::WebContents* web_contents);
 
   // MediaRouterDialogController:
   void CreateMediaRouterDialog() override;
   void CloseMediaRouterDialog() override;
   bool IsShowingMediaRouterDialog() const override;
 
   void CancelPresentationRequest();
 
   base::android::ScopedJavaGlobalRef<jobject> java_dialog_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterDialogControllerAndroid);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ANDROID_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_ANDROID_H_