Invalidate all weak pointers during Decrypting{Audio|Video}Decoder::Stop().

media/filters/decrypting_audio_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_audio_decoder.h"
 
 #include <cstdlib>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 131 matching lines @@
   }
 
   DCHECK(read_cb_.is_null());
   DoReset();
 }
 
 void DecryptingAudioDecoder::Stop(const base::Closure& closure) {
   DVLOG(2) << "Stop() - state: " << state_;
   DCHECK(task_runner_->BelongsToCurrentThread());
 
+  // Invalidate all weak pointers so that pending callbacks won't be fired into
+  // this object.
+  weak_factory_.InvalidateWeakPtrs();
+
   if (decryptor_) {
     decryptor_->RegisterNewKeyCB(Decryptor::kAudio, Decryptor::NewKeyCB());
     decryptor_->DeinitializeDecoder(Decryptor::kAudio);
     decryptor_ = NULL;
   }
   if (!set_decryptor_ready_cb_.is_null())
     base::ResetAndReturn(&set_decryptor_ready_cb_).Run(DecryptorReadyCB());
   pending_buffer_to_decode_ = NULL;
   if (!init_cb_.is_null())
     base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
   if (!read_cb_.is_null())
     base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
   if (!reset_cb_.is_null())
     base::ResetAndReturn(&reset_cb_).Run();
+
   state_ = kStopped;
   task_runner_->PostTask(FROM_HERE, closure);
 }
 
 int DecryptingAudioDecoder::bits_per_channel() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return bits_per_channel_;
 }
 
 ChannelLayout DecryptingAudioDecoder::channel_layout() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return channel_layout_;
 }
 
 int DecryptingAudioDecoder::samples_per_second() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return samples_per_second_;
 }
 
 DecryptingAudioDecoder::~DecryptingAudioDecoder() {
   DCHECK(state_ == kUninitialized || state_ == kStopped) << state_;
 }
 
 void DecryptingAudioDecoder::SetDecryptor(Decryptor* decryptor) {
   DVLOG(2) << "SetDecryptor()";
   DCHECK(task_runner_->BelongsToCurrentThread());
-
-  if (state_ == kStopped)

[acolwell GONE FROM CHROMIUM, 2014/02/18 18:07:24]

nit: DCHECK_NE(state_, kStopped) here and below to explicitly state that these
shouldn't ever be called in the kStopped state.

[xhwang, 2014/02/18 18:46:11]

We check below that 
DCHECK_EQ(state_, kDecryptorRequested) << state_;
which excludes this possibility.

-    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);
     // TODO(xhwang): Add kError state. See http://crbug.com/251503
     state_ = kStopped;
@@ skipping 19 matching lines @@
   state_ = kPendingDecoderInit;
   decryptor_->InitializeAudioDecoder(
       config,
       BindToCurrentLoop(base::Bind(
           &DecryptingAudioDecoder::FinishInitialization, weak_this_)));
 }
 
 void DecryptingAudioDecoder::FinishInitialization(bool success) {
   DVLOG(2) << "FinishInitialization()";
   DCHECK(task_runner_->BelongsToCurrentThread());
-
-  if (state_ == kStopped)
-    return;
-
   DCHECK_EQ(state_, kPendingDecoderInit) << state_;
   DCHECK(!init_cb_.is_null());
   DCHECK(reset_cb_.is_null());  // No Reset() before initialization finished.
   DCHECK(read_cb_.is_null());  // No Read() before initialization finished.
 
   if (!success) {
     base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
     state_ = kStopped;
     return;
   }
@@ skipping 119 matching lines @@
       BindToCurrentLoop(base::Bind(
           &DecryptingAudioDecoder::DeliverFrame, weak_this_, buffer_size)));
 }
 
 void DecryptingAudioDecoder::DeliverFrame(
     int buffer_size,
     Decryptor::Status status,
     const Decryptor::AudioBuffers& frames) {
   DVLOG(3) << "DeliverFrame() - status: " << status;
   DCHECK(task_runner_->BelongsToCurrentThread());
-
-  if (state_ == kStopped)
-    return;
-
   DCHECK_EQ(state_, kPendingDecode) << state_;
   DCHECK(!read_cb_.is_null());
   DCHECK(pending_buffer_to_decode_.get());
   DCHECK(queued_audio_frames_.empty());
 
   bool need_to_try_again_if_nokey_is_returned = key_added_while_decode_pending_;
   key_added_while_decode_pending_ = false;
 
   scoped_refptr<DecoderBuffer> scoped_pending_buffer_to_decode =
       pending_buffer_to_decode_;
@@ skipping 110 matching lines @@
     }
 
     frame->set_timestamp(current_time);
     frame->set_duration(
         timestamp_helper_->GetFrameDuration(frame->frame_count()));
     timestamp_helper_->AddFrames(frame->frame_count());
   }
 }
 
 }  // namespace media