Fix premature access on m_fifo in AudioDestination.

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..f464e9dc4a0ff24a610e4c5df8291ee5a87941ae 100644
--- a/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
+++ b/third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp
@@ -83,33 +83,6 @@ 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) {
-#if OS(ANDROID)
-  if (!outputBus) {
-    // Log when outputBus or FIFO object is invalid. (crbug.com/692423)
-    LOG(WARNING) << "[WebAudio/PushPullFIFO::pull <" << static_cast<void*>(this)
-                 << ">] |outputBus| is invalid.";
-    // Silently return to avoid crash.
-    return;
-  }
-
-  // The following checks are in place to catch the inexplicable crash.
-  // (crbug.com/692423)
-  if (framesRequested > outputBus->length()) {
-    LOG(WARNING) << "[WebAudio/PushPullFIFO::pull <" << static_cast<void*>(this)
-                 << ">] framesRequested > outputBus->length() ("
-                 << framesRequested << " > " << outputBus->length() << ")";
-  }
-  if (framesRequested > m_fifoLength) {
-    LOG(WARNING) << "[WebAudio/PushPullFIFO::pull <" << static_cast<void*>(this)
-                 << ">] framesRequested > m_fifoLength (" << framesRequested
-                 << " > " << m_fifoLength << ")";
-  }
-  if (m_indexRead >= m_fifoLength) {
-    LOG(WARNING) << "[WebAudio/PushPullFIFO::pull <" << static_cast<void*>(this)
-                 << ">] m_indexRead >= m_fifoLength (" << m_indexRead
-                 << " >= " << m_fifoLength << ")";
-  }
-#endif

[Raymond Toy, 2017/03/10 21:11:09]

Why get rid of all of these prints? They might not show up in the crash reports
but they seem useful if we could ever see the problem locally.

[hongchan, 2017/03/10 21:13:55]

Hmm. I thought we agreed upon deleting these for the fix. I will put them back
after M58 branching.

   CHECK(outputBus);
   SECURITY_CHECK(framesRequested <= outputBus->length());
   SECURITY_CHECK(framesRequested <= m_fifoLength);