Add decoder de-initialize and reset to the Pepper CDM API.

ppapi/api/private/ppb_content_decryptor_private.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_ContentDecryptor_Private</code>
  * interface. Note: This is a special interface, only to be used for Content
  * Decryption Modules, not normal plugins.
  */
 label Chrome {
-  M23 = 0.2
+  M24 = 0.3
 };
 
 /**
  * <code>PPB_ContentDecryptor_Private</code> structure contains the function
  * pointers the browser must implement to support plugins implementing the
  * <code>PPP_ContentDecryptor_Private</code> interface. This interface provides
  * browser side support for the Content Decryption Module (CDM) for v0.1 of the
  * proposed Encrypted Media Extensions: http://goo.gl/rbdnR
  */
 interface PPB_ContentDecryptor_Private {
@@ skipping 116 matching lines @@
    * @param[in] decrypted_block_info A <code>PP_DecryptedBlockInfo</code> that
    * contains the result code and tracking info associated with the
    * <code>decrypted_block</code>.
    */
   void DeliverBlock(
       [in] PP_Instance instance,
       [in] PP_Resource decrypted_block,
       [in] PP_DecryptedBlockInfo decrypted_block_info);
 
   /**
+   * Called after the <code>ResetAudioDecoder()</code> or

[Ami GONE FROM CHROMIUM, 2012/10/09 07:26:38]

This CL talks about Audio-related methods that don't exist yet.
Not sure how ppapi/OWNERS want to handle that; you might ask explicitly.

[Tom Finegan, 2012/10/10 00:39:32]

Good point. I'll ask Brett once we finish reviewing among ourselves.

+   * <code>ResetVideoDecoder()</code> method on the
+   * <code>PPP_ContentDecryptor_Private</code> interface completes to report
+   * decoder reset completion to the browser.
+   *
+   * @param[in] request_id The <code>request_id</code> value passed to
+   * <code>ResetAudioDecoder</code> or <code>ResetVideoDecoder</code>.
+   */
+  void DecoderReset(

[Ami GONE FROM CHROMIUM, 2012/10/09 07:25:54]

s/Reset/ResetDone/ ?  (to clarify observation vs. request)

[xhwang, 2012/10/09 16:27:27]

These two methods are not needed for now, at least in the current plan (using
request id to track callbacks and cancel them immediately upon reset/stop in
PluginInstance instead of waiting for reset/stop to finish).

All pending callbacks (e.g. decrypt_cb in Decrypt(), init_cb in
InitializeVideoDecoder()) are tracked with request ids. So when we cancel, we
can just fire them in the PluginInstance and don't need to wait for the
plugin/cdm to return.

WDYT? +ddorwin/fischman for comments.

[Ami GONE FROM CHROMIUM, 2012/10/09 16:41:05]

I'm not sure what you're asking.
I thought this was Tom's partial impl of what we discussed, replacing request_id
with callbacks.  

[xhwang, 2012/10/09 18:41:20]

Chatted with fischman offline again. We'll need reset/stop completion callback
in the future. So please keep these functions.

About request ID, if we drop them, we need a way to distinguish between auido
and video in these shared PPB calls about which decode is reset/stopped. Same
for DeliverBlock.

Let's keep the request IDs for now and update them later.

[Tom Finegan, 2012/10/10 00:39:32]

The request IDs remain, and this method has been renamed to DecoderResetDone.

+      [in] PP_Instance instance,
+      [in] uint32_t request_id);
+
+  /**
+   * Called after the <code>StopAudioDecoder()</code> or
+   * <code>StopVideoDecoder()</code> method on the
+   * <code>PPP_ContentDecryptor_Private</code> interface completes to report
+   * decoder stop completion to the browser.
+   *
+   * @param[in] request_id The <code>request_id</code> value passed to
+   * <code>StopAudioDecoder</code> or <code>StopVideoDecoder</code>.
+   */
+  void DecoderStopped(

[Ami GONE FROM CHROMIUM, 2012/10/09 07:25:54]

s/Stopped/StopDone/

[Tom Finegan, 2012/10/10 00:39:32]

Done.

+      [in] PP_Instance instance,
+      [in] uint32_t request_id);
+
+  /**
    * Called after the <code>DecryptAndDecode()</code> method on the
    * <code>PPP_ContentDecryptor_Private</code> interface completes to deliver
    * a decrypted and decoded video frame to the browser for rendering.
    *
    * @param[in] decrypted_frame A <code>PP_Resource</code> corresponding to a
    * <code>PPB_Buffer_Dev</code> resource that contains a video frame.
    *
    * @param[in] decrypted_frame_info A <code>PP_DecryptedFrameInfo</code> that
    * contains the result code, tracking info, and buffer format associated with
    * <code>decrypted_frame</code>.
@@ skipping 15 matching lines @@
    *
    * @param[in] decrypted_block_info A <code>PP_DecryptedBlockInfo</code> that
    * contains the tracking info and result code associated with the
    * <code>decrypted_block</code>.
    */
   void DeliverSamples(
       [in] PP_Instance instance,
       [in] PP_Resource decrypted_samples,
       [in] PP_DecryptedBlockInfo decrypted_block_info);
 };