Add PPAPI decryptor interfaces.

ppapi/api/private/ppp_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>PPP_ContentDecryptor_Private</code>
+ * interface.
+ */
+label Chrome {
+  M23 = 0.1
+};
+
+/**
+ * <code>PPP_ContentDecryptor_Private</code> structure contains the function
+ * pointers the decryption plugin MUST implement to provide services needed by
+ * the browser. This interface provides the plugin side support for the CDM for
+ * v0.1 of the proposed Encrypted Media Extensions: http://goo.gl/rbdnR
+ *
+ * Note: This is a special interface, only to be used for Content Decryption
+ * Modules, not normal plugins.

[dmichael (off chromium), 2012/08/14 16:54:12]

I think it would still be useful to have a note like this here; conventional
plugins should not implement this interface.

+ */
+interface PPP_ContentDecryptor_Private {
+  /**
+   * Generates a key request. key_system specifies the key or licensing system
+   * to use. init_data is a data buffer containing data for use in generating
+   * the request.
+   *
+   * Note: <code>GenerateKeyRequest()</code> is responsible for creating the
+   * session ID used in other methods on this interface. The session ID will be

[dmichael (off chromium), 2012/08/14 03:31:37]

active voice...  "The CDM [should|must] provide the session ID to the
browser..."

[Tom Finegan, 2012/08/14 16:39:40]

Done.

+   * provided to the browser via <code>KeyMessage()</code> on the
+   * <code>PPB_ContentDecryptor_Private</code> interface.
+   *
+   * @param[in] key_system A <code>PP_Var</code> of type
+   * <code>PP_VARTYPE_STRING</code> containing the name of the key system.
+   *
+   * @param[in] init_data A <code>PP_Var</code> of type
+   * <code>PP_VARTYPE_ARRAYBUFFER</code> containing container specific
+   * initialization data.
+   */
+  PP_Bool GenerateKeyRequest(
+      [in] PP_Instance instance,
+      [in] PP_Var key_system,
+      [in] PP_Var init_data);
+
+  /**
+   * Provides a key or license to the decryptor for decrypting media data.

[dmichael (off chromium), 2012/08/14 03:31:37]

Does the CDM call back to the browser at all for this one? If so, please note it
(same for any methods for which the browser expects a response).

[Tom Finegan, 2012/08/14 16:39:40]

Done.

+   *
+   * @param[in] session_id A <code>PP_Var</code> of type
+   * <code>PP_VARTYPE_STRING</code> containing the session ID.
+   *
+   * @param[in] key A <code>PP_Var</code> of type
+   * <code>PP_VARTYPE_ARRAYBUFFER</code> containing the decryption key, license,
+   * or other message for the given session ID.
+   */
+  PP_Bool AddKey(
+      [in] PP_Instance instance,
+      [in] PP_Var session_id,
+      [in] PP_Var key);
+
+  /**
+   * Cancels a pending key request for the specified session ID.
+   *
+   * @param[in] session_id A <code>PP_Var</code> of type
+   * <code>PP_VARTYPE_STRING</code> containing the session ID.
+   */
+  PP_Bool CancelKeyRequest(
+      [in] PP_Instance instance,
+      [in] PP_Var session_id);
+
+  /**
+   * Decrypts the block and returns the unencrypted block via
+   * <code>DeliverBlock()</code> on the
+   * <code>PPB_ContentDecryptor_Private</code> interface. The returned block
+   * contains encoded data.
+   *
+   * @param[in] resource A <code>PP_Resource</code> corresponding to a
+   * <code>PPB_Buffer_Dev</code> resource that contains an encrypted data
+   * block.
+   *
+   * @param[in] request_id A value used by the browser to associate data
+   * returned via the <code>PPB_ContentDecryptor_Private</code> interface with
+   * decryption method calls.
+   */
+  PP_Bool Decrypt(
+      [in] PP_Instance instance,
+      [in] PP_Resource encrypted_block,
+      [in] int32_t request_id);
+
+  /**
+   * Decrypts the block, decodes it, and returns the unencrypted uncompressed
+   * (decoded) media to the browser via the
+   * <code>PPB_ContentDecryptor_Private</code> interface.
+   *
+   * Decrypted and decoded video frames are sent to <code>DeliverFrame()</code>,
+   * while audio samples are sent to <code>DeliverSamples()</code>.
+   *
+   * @param[in] resource A <code>PP_Resource</code> corresponding to a
+   * <code>PPB_Buffer_Dev</code> resource that contains an encrypted data
+   * block.
+   *
+   * @param[in] request_id A value used by the browser to associate data
+   * returned via the <code>PPB_ContentDecryptor_Private</code> interface with
+   * decryption method calls.
+   */
+  PP_Bool DecryptAndDecode(
+      [in] PP_Instance instance,
+      [in] PP_Resource encrypted_block,
+      [in] int32_t request_id);
+};