[Media Router] 2nd take on fix route response callback lifetime in UI.

chrome/browser/ui/webui/media_router/media_router_dialog_controller.h

Index: chrome/browser/ui/webui/media_router/media_router_dialog_controller.h
diff --git a/chrome/browser/ui/webui/media_router/media_router_dialog_controller.h b/chrome/browser/ui/webui/media_router/media_router_dialog_controller.h
index f357d00bb173adb44d65fe467591b1280f31dc7a..19ce9a5d5e1e90fcc3363322d191974c5db2ac17 100644
--- a/chrome/browser/ui/webui/media_router/media_router_dialog_controller.h
+++ b/chrome/browser/ui/webui/media_router/media_router_dialog_controller.h
@@ -6,7 +6,9 @@
 #define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_DIALOG_CONTROLLER_H_
 
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/media/router/create_session_request.h"
+#include "chrome/browser/media/router/media_router.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
@@ -50,9 +52,26 @@ class MediaRouterDialogController
   // It is an error to call this function if there is currently no dialog.
   void CloseMediaRouterDialog();
 
+  // Called by the dialog when it is about to make a presentation route request
+  // to ensure the response can be received and handled properly even when
+  // the dialog is destroyed while the request is in progress.
+  // Returns a MediaRouteResponseCallback that can be used to be used as the
+  // callback argument in |MediaRouter::CreateRoute()|.
+  // |route_response_callback|: Callback to the dialog to invoke when the
+  // presentation route response comes back, if the dialog still exists.
+  // |presentation_request|: The Presentation API request to respond to when
+  // route reponse comes back, or nullptr if the presentation route request

[Kevin M, 2015/07/13 21:55:26]

Suggestion: ...or nullptr if the request did not originate from the Presentation
API.

[imcheng, 2015/07/14 01:00:24]

Done.

+  // does not correspond to a Presentation API request (i.e. browser initiated).
+  MediaRouteResponseCallback AddPresentationRouteRequest(
+      const MediaRouteResponseCallback& route_response_callback,
+      scoped_ptr<CreateSessionRequest> presentation_request);
+
  private:
   class DialogWebContentsObserver;
   class InitiatorWebContentsObserver;
+  class MediaRouterDialogCallbacks;
+  class BrowserInitiatedMediaRouterDialogCallbacks;

[Kevin M, 2015/07/13 21:55:26]

alpha sort?

[imcheng, 2015/07/14 01:00:24]

Done.

+  class PresentationMediaRouterDialogCallbacks;
   friend class content::WebContentsUserData<MediaRouterDialogController>;
 
   // Use MediaRouterDialogController::CreateForWebContents() to create an
@@ -70,6 +89,12 @@ class MediaRouterDialogController
 
   void PopulateDialog(content::WebContents* media_router_dialog);
 
+  // Destroys |callbacks| by removing it from |pending_dialog_callbacks_|.
+  // Called by MediaRouterDialogCallbacks after it receives route response and
+  // is done processing it.
+  // |callbacks|: The MediaRouterDialogCallbacks to destroy.
+  void DestroyDialogCallbacks(MediaRouterDialogCallbacks* callbacks);
+
   scoped_ptr<InitiatorWebContentsObserver> initiator_observer_;
   scoped_ptr<DialogWebContentsObserver> dialog_observer_;
 
@@ -84,6 +109,11 @@ class MediaRouterDialogController
   // passed to the MediaRouterUI when it is initialized.
   scoped_ptr<CreateSessionRequest> presentation_request_;
 
+  // MediaRouterDialogCallbacks corresponding to presentation route requests
+  // made from dialogs created from this instance. Note that they may outlive
+  // their corresponding dialogs.
+  ScopedVector<MediaRouterDialogCallbacks> pending_dialog_callbacks_;
+
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterDialogController);