EME: Address TODOs related to the removal of prefixed EME

media/cdm/ppapi/external_clear_key/clear_key_cdm.cc

 // Copyright 2013 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.
 
 #include "media/cdm/ppapi/external_clear_key/clear_key_cdm.h"
 
 #include <algorithm>
 #include <cstring>
 #include <sstream>
 #include <utility>
@@ skipping 317 matching lines @@
 
   // Only allowed to successfully load this session once.
   DCHECK(session_id_for_emulated_loadsession_.empty());
 
   std::unique_ptr<media::NewSessionCdmPromise> promise(
       new media::CdmCallbackPromise<std::string>(
           base::Bind(&ClearKeyCdm::OnSessionLoaded, base::Unretained(this),
                      promise_id),
           base::Bind(&ClearKeyCdm::OnPromiseFailed, base::Unretained(this),
                      promise_id)));
+  // AesDecryptor does not support loading, but we need a real session so create

[ddorwin, 2016/08/11 20:28:32]

Is this comment accurate?

[jrummell, 2016/08/12 19:24:25]

How about "AesDecryptor does not support loading, so create a temporary session
with fake initData to represent it."?

[ddorwin, 2016/08/12 21:40:38]

Done.

+  // one with fake initData.
   decryptor_->CreateSessionAndGenerateRequest(
       MediaKeys::TEMPORARY_SESSION, EmeInitDataType::WEBM,
-      std::vector<uint8_t>(), std::move(promise));
+      std::vector<uint8_t>(16), std::move(promise));

[ddorwin, 2016/08/11 20:28:32]

Made this 128 (random) bits. 0 bytes failed the check in aes_decryptor.cc.

[jrummell, 2016/08/12 19:24:25]

The keyId used is kLoadableSessionKeyId. So it could be used here, but it is
ignored in OnSessionMessage. However, it might be more explicit if that key was
used here (since that is the intent).

[ddorwin, 2016/08/12 21:40:38]

Done.

 }
 
 void ClearKeyCdm::UpdateSession(uint32_t promise_id,
                                 const char* session_id,
                                 uint32_t session_id_length,
                                 const uint8_t* response,
                                 uint32_t response_size) {
   DVLOG(1) << __FUNCTION__;
   std::string web_session_str(session_id, session_id_length);
 
@@ skipping 562 matching lines @@
 void ClearKeyCdm::OnFileIOTestComplete(bool success) {
   DVLOG(1) << __FUNCTION__ << ": " << success;
   std::string message = GetFileIOTestResultMessage(success);
   host_->OnSessionMessage(last_session_id_.data(), last_session_id_.length(),
                           cdm::kLicenseRequest, message.data(),
                           message.length(), NULL, 0);
   file_io_test_runner_.reset();
 }
 
 }  // namespace media