support video device enumeration from renderer process.

content/browser/renderer_host/media/media_stream_manager.h

 // Copyright (c) 2011 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.
 
-// MediaStreamManager is used to open media capture devices (video supported
-// now). Call flow:
+// MediaStreamManager is used to open/enumerate media capture devices (video
+// supported now). Call flow:
 // 1. GenerateStream is called when a render process wants to use a capture
 //    device.
 // 2. MediaStreamManager will ask MediaStreamDeviceSettings for permission to
 //    use devices and for which device to use.
-// 3. MediaStreamDeviceSettings will request list(s) of available devices, the
-//    requests will be relayed to the corresponding media device manager and the
-//    result will be given to MediaStreamDeviceSettings.
+// 3. MediaStreamManager will request the corresponding media device manager(s)
+//    to enumerate available devices. The result will be given to
+//    MediaStreamDeviceSettings.
 // 4. MediaStreamDeviceSettings will, by using user settings, pick devices which
 //    devices to use and let MediaStreamManager know the result.
 // 5. MediaStreamManager will call the proper media device manager to open the
 //    device and let the MediaStreamRequester know it has been done.
 
+// When enumeration and open are done in separate operations,
+// MediaStreamDeviceSettings is not involved as in steps.
+
 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/ref_counted.h"
@@ skipping 35 matching lines @@
                       int render_view_id, const StreamOptions& options,
                       const std::string& security_origin, std::string* label);
 
   // Cancels all non-finished GenerateStream request, i.e. request for which
   // StreamGenerated hasn't been called.
   void CancelRequests(MediaStreamRequester* requester);
 
   // Closes generated stream.
   void StopGeneratedStream(const std::string& label);
 
+  // Gets a list of devices of |type|.
+  // The request is identified using |label|, which is pointing to a
+  // std::string.
+  void EnumerateDevices(MediaStreamRequester* requester,
+                        int render_process_id,
+                        int render_view_id,
+                        MediaStreamType type,
+                        const std::string& security_origin,
+                        std::string* label);
+
+  // Open a device identified by |device_id|.
+  // The request is identified using |label|, which is pointing to a
+  // std::string.
+  void OpenDevice(MediaStreamRequester* requester,
+                  int render_process_id,
+                  int render_view_id,
+                  const std::string& device_id,
+                  MediaStreamType type,
+                  const std::string& security_origin,
+                  std::string* label);
+
   // Implements MediaStreamProviderListener.
   virtual void Opened(MediaStreamType stream_type,
                       int capture_session_id) OVERRIDE;
   virtual void Closed(MediaStreamType stream_type,
                       int capture_session_id) OVERRIDE;
   virtual void DevicesEnumerated(MediaStreamType stream_type,
                                  const StreamDeviceInfoArray& devices) OVERRIDE;
   virtual void Error(MediaStreamType stream_type,
                      int capture_session_id,
                      MediaStreamProviderError error) OVERRIDE;
 
   // Implements SettingsRequester.
-  virtual void GetDevices(const std::string& label,
-                          MediaStreamType stream_type) OVERRIDE;
   virtual void DevicesAccepted(const std::string& label,
                                const StreamDeviceInfoArray& devices) OVERRIDE;
   virtual void SettingsError(const std::string& label) OVERRIDE;
 
   // Used by unit test to make sure fake devices are used instead of a real
   // devices, which is needed for server based testing.
   void UseFakeDevice();
 
  private:
   // Contains all data needed to keep track of requests.
   struct DeviceRequest;
 
   // Helpers.
   bool RequestDone(const MediaStreamManager::DeviceRequest& request) const;
   MediaStreamProvider* GetDeviceManager(MediaStreamType stream_type);
+  void StartEnumeration(DeviceRequest* new_request,
+                        int render_process_id,
+                        int render_view_id,
+                        const std::string& security_origin,
+                        std::string* label);
 
   scoped_ptr<MediaStreamDeviceSettings> device_settings_;
   scoped_ptr<VideoCaptureManager> video_capture_manager_;
   scoped_ptr<AudioInputDeviceManager> audio_input_device_manager_;
 
   // Keeps track of device types currently being enumerated to not enumerate
   // when not necessary.
   std::vector<bool> enumeration_in_progress_;
 
   // All non-closed request.
   typedef std::map<std::string, DeviceRequest> DeviceRequests;
   DeviceRequests requests_;
   scoped_refptr<AudioManager> audio_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamManager);
 };
 
 }  // namespace media_stream
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_