Support cancellation of request for opening device.

content/renderer/media/media_stream_dispatcher.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_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_
 
 #include <list>
 #include <map>
 #include <string>
@@ skipping 30 matching lines @@
   // Request a new media stream to be created.
   // This can be used either by WebKit or a plugin.
   // Note: The event_handler must be valid for as long as the stream exists.
   virtual void GenerateStream(
       int request_id,
       const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
       const StreamOptions& components,
       const GURL& security_origin);
 
   // Cancel the request for a new media stream to be created.
-  virtual void CancelGenerateStream(int request_id);
+  virtual void CancelGenerateStream(
+      int request_id,
+      const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler);
 
   // Stop a started stream. Label is the label provided in OnStreamGenerated.
   virtual void StopStream(const std::string& label);
 
   // Request to enumerate devices.
   void EnumerateDevices(
       int request_id,
       const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
       MediaStreamType type,
       const GURL& security_origin);
 
   // Request to stop enumerating devices.
   void StopEnumerateDevices(
       int request_id,
       const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler);
 
   // Request to open a device.
   void OpenDevice(
       int request_id,
       const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
       const std::string& device_id,
       MediaStreamType type,
       const GURL& security_origin);
 
+  // Cancel the request to open a device.
+  virtual void CancelOpenDevice(
+      int request_id,
+      const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler);
+
   // Close a started device. |label| is provided in OnDeviceOpened.
   void CloseDevice(const std::string& label);
 
   // Check if the label is a valid stream.
   virtual bool IsStream(const std::string& label);
   // Get the video session_id given a label. The label identifies a stream.
   // index is the index in the video_device_array of the stream.
   virtual int video_session_id(const std::string& label, int index);
   // Returns an audio session_id given a label and an index.
   virtual int audio_session_id(const std::string& label, int index);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, BasicStream);
   FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, BasicStreamForDevice);
   FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, BasicVideoDevice);
   FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, TestFailure);
   FRIEND_TEST_ALL_PREFIXES(MediaStreamDispatcherTest, CancelGenerateStream);
 
   struct Request;
 
   // Private class for keeping track of opened devices and who have
   // opened it.
   struct Stream;
 
+  // An enumeration request is identified by pair (request_id, handler).
+  // It allows multiple clients to make requests and each client could have
+  // its own request_id sequence.
   struct EnumerationRequest {
     EnumerationRequest(
         const base::WeakPtr<MediaStreamDispatcherEventHandler>& handler,
         int request_id);
     ~EnumerationRequest();
+    bool IsThisRequest(
+        int request_id,
+        const base::WeakPtr<MediaStreamDispatcherEventHandler>& handler);
 
     base::WeakPtr<MediaStreamDispatcherEventHandler> handler;
     int request_id;
   };
 
   // List of requests made to EnumerateDevices.
   typedef std::list<EnumerationRequest> EnumerationRequestList;
 
   struct EnumerationState {
     EnumerationState();
@@ skipping 47 matching lines @@
   // List of calls made to GenerateStream that have not yet completed.
   typedef std::list<Request> RequestList;
   RequestList requests_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamDispatcher);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_H_