Encrypted Media: DecryptingXxx::SetDecryptor() accepts NULL decryptor.

media/filters/decrypting_video_decoder.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 "media/filters/decrypting_video_decoder.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
@@ skipping 153 matching lines @@
   DCHECK(message_loop_->BelongsToCurrentThread());
 
   if (state_ == kStopped)
     return;
 
   DCHECK_EQ(state_, kDecryptorRequested) << state_;
   DCHECK(!init_cb_.is_null());
   DCHECK(!set_decryptor_ready_cb_.is_null());
   set_decryptor_ready_cb_.Reset();
 
+  if (!decryptor) {
+    base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
+    state_ = kStopped;
+    return;
+  }
+
   decryptor_ = decryptor;
 
   state_ = kPendingDecoderInit;
   decryptor_->InitializeVideoDecoder(
       demuxer_stream_->video_decoder_config(), BindToCurrentLoop(base::Bind(
           &DecryptingVideoDecoder::FinishInitialization, weak_this_)));
 }
 
 void DecryptingVideoDecoder::FinishInitialization(bool success) {
   DVLOG(2) << "FinishInitialization()";
@@ skipping 177 matching lines @@
 }
 
 void DecryptingVideoDecoder::DoReset() {
   DCHECK(init_cb_.is_null());
   DCHECK(read_cb_.is_null());
   state_ = kIdle;
   base::ResetAndReturn(&reset_cb_).Run();
 }
 
 }  // namespace media