Implement device enumeration for PPB_VideoCapture_Dev.

ppapi/api/dev/ppb_video_capture_dev.idl

 /* 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.
  */
 
 /**
  * This file defines the <code>PPB_VideoCapture_Dev</code> interface.
  */
 label Chrome {
-  M14 = 0.1
+  M14 = 0.1,
+  M18 = 0.2
 };
 
 /**
  * Video capture interface. It goes hand-in-hand with PPP_VideoCapture_Dev.
  *
  * Theory of operation:
  * 1- Create a VideoCapture resource using Create.
  * 2- Start the capture using StartCapture. You pass in the requested info
  * (resolution, frame rate), as well as suggest a number of buffers you will
  * need.
@@ skipping 24 matching lines @@
   /**
    * Returns PP_TRUE if the given resource is a VideoCapture.
    */
   PP_Bool IsVideoCapture(
       [in] PP_Resource video_capture);
 
   /**
    * Starts the capture. |requested_info| is a pointer to a structure containing
    * the requested resolution and frame rate. |buffer_count| is the number of
    * buffers requested by the plugin. Note: it is only used as advisory, the
-   * browser may allocate more of fewer based on available resources.
+   * browser may allocate more or fewer based on available resources.
    * How many buffers depends on usage. At least 2 to make sure latency doesn't
    * cause lost frames. If the plugin expects to hold on to more than one buffer
    * at a time (e.g. to do multi-frame processing, like video encoding), it
    * should request that many more.
    *
    * Returns PP_ERROR_FAILED if called when the capture was already started, or
    * PP_OK on success.
    */
   int32_t StartCapture(

[viettrungluu, 2012/01/27 18:54:34]

Maybe we should deprecate this version (and remove it from 0.2)?

[yzshen1, 2012/01/27 19:20:40]

It won't show up in v0.2. The generator decides to skip it since we have a
method with the same name in v0.2.

I think it is better to mark it explicitly with [version=0.1].

On 2012/01/27 18:54:34, viettrungluu wrote:

       [in] PP_Resource video_capture,
       [in] PP_VideoCaptureDeviceInfo_Dev requested_info,
       [in] uint32_t buffer_count);
 
   /**
+   * Enumerates video capture devices. Once the operation is completed
+   * successfully. |GetDevices()| can be used to retrieve the devices.
+   */
+  [version=0.2]
+  int32_t EnumerateDevices(
+      [in] PP_Resource video_capture,
+      [in] PP_CompletionCallback callback);
+
+  /**
+   * Gets video capture devices. The returned value is a PPB_ResourceArray_Dev
+   * resource if successful, which holds a list of PPB_DeviceRef_Dev resources.
+   */
+  [version=0.2]
+  PP_Resource GetDevices(
+      [in] PP_Resource video_capture);
+
+  /**
+   * Starts the capture. |device_ref| identifies a video capture device. It
+   * could be one of the resource in the array returned by |GetDevices()|, or 0
+   * which means the default device.
+   * |requested_info| is a pointer to a structure containing the requested
+   * resolution and frame rate. |buffer_count| is the number of buffers
+   * requested by the plugin. Note: it is only used as advisory, the browser may
+   * allocate more or fewer based on available resources. How many buffers
+   * depends on usage. At least 2 to make sure latency doesn't cause lost
+   * frames. If the plugin expects to hold on to more than one buffer at a time
+   * (e.g. to do multi-frame processing, like video encoding), it should request
+   * that many more.
+   *
+   * Returns PP_ERROR_FAILED if called when the capture was already started, or
+   * PP_OK on success.
+   */
+  [version=0.2]
+  int32_t StartCapture(
+      [in] PP_Resource video_capture,
+      [in] PP_Resource device_ref,
+      [in] PP_VideoCaptureDeviceInfo_Dev requested_info,
+      [in] uint32_t buffer_count);
+
+  /**
    * Allows the browser to reuse a buffer that was previously sent by
    * PPP_VideoCapture_Dev.OnBufferReady. |buffer| is the index of the buffer in
    * the array returned by PPP_VideoCapture_Dev.OnDeviceInfo.
    *
    * Returns PP_ERROR_BADARGUMENT if buffer is out of range (greater than the
    * number of buffers returned by PPP_VideoCapture_Dev.OnDeviceInfo), or if it
    * is not currently owned by the plugin. Returns PP_OK otherwise.
    */
   int32_t ReuseBuffer(
       [in] PP_Resource video_capture,
       [in] uint32_t buffer);
 
   /**
    * Stops the capture.
    *
    * Returns PP_ERROR_FAILED if the capture wasn't already started, or PP_OK on
    * success.
    */
   int32_t StopCapture(
       [in] PP_Resource video_capture);
 };