Refactor: Make MediaCaptureDevicesDispatcher have pluggable handlers.

chrome/browser/media/permission_bubble_media_access_handler.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_PERMISSION_BUBBLE_MEDIA_ACCESS_HANDLER_H_
+#define CHROME_BROWSER_MEDIA_PERMISSION_BUBBLE_MEDIA_ACCESS_HANDLER_H_
+
+#include "chrome/browser/media/media_access_handler.h"
+
+struct PendingAccessRequest {
+  PendingAccessRequest(const content::MediaStreamRequest& request,
+                       const content::MediaResponseCallback& callback);
+  ~PendingAccessRequest();
+
+  // TODO(gbillock): make the MediaStreamDevicesController owned by
+  // this object when we're using bubbles.
+  content::MediaStreamRequest request;
+  content::MediaResponseCallback callback;
+};
+
+typedef std::deque<PendingAccessRequest> RequestsQueue;
+typedef std::map<content::WebContents*, RequestsQueue> RequestsQueues;
+
+class PermissionBubbleMediaAccessHandler : public MediaAccessHandler {
+ public:
+  explicit PermissionBubbleMediaAccessHandler(RequestsQueues* requests);
+  ~PermissionBubbleMediaAccessHandler() override;
+
+  // MediaAccessHandler implementation.
+  bool SupportsRequest(const content::MediaStreamRequest& request,
+                       const extensions::Extension* extension) override;
+  void HandleRequest(content::WebContents* web_contents,
+                     const content::MediaStreamRequest& request,
+                     const content::MediaResponseCallback& callback,
+                     const extensions::Extension* extension) override;
+
+ private:
+  void ProcessQueuedAccessRequest(content::WebContents* web_contents);
+  void OnAccessRequestResponse(content::WebContents* web_contents,
+                               const content::MediaStreamDevices& devices,
+                               content::MediaStreamRequestResult result,
+                               scoped_ptr<content::MediaStreamUI> ui);
+
+  RequestsQueues* pending_requests_;
+};
+#endif  // CHROME_BROWSER_MEDIA_PERMISSION_BUBBLE_MEDIA_ACCESS_HANDLER_H_