Add WebThread in AudioDestination to support AudioWorkletThread

third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp

Index: third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
diff --git a/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp b/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
index 73b1ef44bf04591cdc283b1de4bf808e7b6e8ee8..dca17659afa49db997bfa41c5421307c038c8ecd 100644
--- a/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
+++ b/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
@@ -34,6 +34,8 @@ PushPullFIFO::~PushPullFIFO() {}
 // Push the data from |inputBus| to FIFO. The size of push is determined by
 // the length of |inputBus|.
 void PushPullFIFO::push(const AudioBus* inputBus) {
+  MutexLocker lock(m_threadMutex);
+
   CHECK(inputBus);
   CHECK_EQ(inputBus->length(), AudioUtilities::kRenderQuantumFrames);
   SECURITY_CHECK(inputBus->length() <= m_fifoLength);
@@ -83,6 +85,8 @@ void PushPullFIFO::push(const AudioBus* inputBus) {
 // Pull the data out of FIFO to |outputBus|. If remaining frame in the FIFO
 // is less than the frames to pull, provides remaining frame plus the silence.
 void PushPullFIFO::pull(AudioBus* outputBus, size_t framesRequested) {
+  MutexLocker lock(m_threadMutex);
+
 #if OS(ANDROID)
   if (!outputBus) {
     // Log when outputBus or FIFO object is invalid. (crbug.com/692423)
@@ -164,7 +168,18 @@ void PushPullFIFO::pull(AudioBus* outputBus, size_t framesRequested) {
   DCHECK_EQ((m_indexRead + m_framesAvailable) % m_fifoLength, m_indexWrite);
 }
 
+size_t PushPullFIFO::framesAvailable() const {
+  MutexLocker lock(m_threadMutex);
+  return m_framesAvailable;

[o1ka, 2017/03/30 13:17:05]

This is correct but unfortunate to have a lock here, as we discussed - we want
to minimize locking. That's why I propose to refactor the code and to get rid of
this method.

[hongchan, 2017/03/30 18:36:00]

Acknowledged.

+}
+
+AudioBus* PushPullFIFO::getFIFOBusForTest() const {
+  MutexLocker lock(m_threadMutex);
+  return m_fifoBus.get();
+}
+
 const PushPullFIFOStateForTest PushPullFIFO::getStateForTest() const {
+  MutexLocker lock(m_threadMutex);
   return {length(),     numberOfChannels(), framesAvailable(), m_indexRead,
           m_indexWrite, m_overflowCount,    m_underflowCount};
 }