Verify promise type before casting.

content/renderer/pepper/content_decryptor_delegate.cc

 // 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.
 
 #include "content/renderer/pepper/content_decryptor_delegate.h"
 
 #include "base/callback_helpers.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/numerics/safe_conversions.h"
@@ skipping 607 matching lines @@
 
   // TODO(tomfinegan): Need to get stream type from media stack.
   ScopedPPResource pp_resource(encrypted_resource.get());
   plugin_decryption_interface_->DecryptAndDecode(
       pp_instance_, PP_DECRYPTORSTREAMTYPE_VIDEO, pp_resource, &block_info);
   return true;
 }
 
 void ContentDecryptorDelegate::OnPromiseResolved(uint32 promise_id) {
   scoped_ptr<CdmPromise> promise = TakePromise(promise_id);
-  if (promise) {
+  DCHECK(promise &&
+         promise->GetResolveParameterType() == media::CdmPromise::VOID_TYPE);
+  if (promise &&
+      promise->GetResolveParameterType() == media::CdmPromise::VOID_TYPE) {
     SimpleCdmPromise* simple_promise(
         static_cast<SimpleCdmPromise*>(promise.get()));
     simple_promise->resolve();
   }

[xhwang, 2014/08/27 22:49:26]

nit: A simpler version:

if (!promise || promise->GetResolveParameterType() !=
media::CdmPromise::VOID_TYPE) {
  NOTREACHED();
  return;
}

// static_cast and resolve...

[jrummell, 2014/08/27 23:05:13]

Done.

 }
 
 void ContentDecryptorDelegate::OnPromiseResolvedWithSession(
     uint32 promise_id,
     PP_Var web_session_id) {
   scoped_ptr<CdmPromise> promise = TakePromise(promise_id);
 
   StringVar* web_session_id_string = StringVar::FromPPVar(web_session_id);
   DCHECK(web_session_id_string);
 
-  if (promise) {
+  DCHECK(promise &&
+         promise->GetResolveParameterType() == media::CdmPromise::STRING_TYPE);
+  if (promise &&
+      promise->GetResolveParameterType() == media::CdmPromise::STRING_TYPE) {

[xhwang, 2014/08/27 22:49:26]

ditto

[jrummell, 2014/08/27 23:05:13]

Done.

     NewSessionCdmPromise* session_promise(
         static_cast<NewSessionCdmPromise*>(promise.get()));
     session_promise->resolve(web_session_id_string->value());
   }
 }
 
 void ContentDecryptorDelegate::OnPromiseRejected(
     uint32 promise_id,
     PP_CdmExceptionCode exception_code,
     uint32 system_code,
@@ skipping 520 matching lines @@
 
 scoped_ptr<CdmPromise> ContentDecryptorDelegate::TakePromise(
     uint32_t promise_id) {
   PromiseMap::iterator it = promises_.find(promise_id);
   if (it == promises_.end())
     return scoped_ptr<CdmPromise>();
   return promises_.take_and_erase(it);
 }
 
 }  // namespace content