Revert 171681

> Delay delivery of audio input data.
> 
> The AudioQueue API may use a large internal buffer and repeatedly call us
> back to back once that internal buffer is filled.  When this happens the
> renderer client does not have enough time to read data back from the
> shared memory before the next write comes along.  If HandleInputBuffer()
> is called too frequently, Sleep() to simulate realtime input and ensure
> the shared memory doesn't get trampled.
> 
> BUG=157613
> TEST=Playback works on older style Mac units.
> 
> Review URL: https://codereview.chromium.org/11482002

TBR=dalecurtis@google.com
Review URL: https://codereview.chromium.org/11478019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171692 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 2 insertions, 24 deletions

diff --git a/media/audio/mac/audio_input_mac.cc b/media/audio/mac/audio_input_mac.cc
index 69791cf..fd2d9be 100644
--- a/media/audio/mac/audio_input_mac.cc
+++ b/media/audio/mac/audio_input_mac.cc
@@ -192,31 +192,12 @@ void PCMQueueInAudioInputStream::HandleInputBuffer(
     return;
   }
 
-  if (audio_buffer->mAudioDataByteSize) {
-    // The AudioQueue API may use a large internal buffer and repeatedly call us
-    // back to back once that internal buffer is filled.  When this happens the
-    // renderer client does not have enough time to read data back from the
-    // shared memory before the next write comes along.  If HandleInputBuffer()
-    // is called too frequently, Sleep() to simulate realtime input and ensure
-    // the shared memory doesn't get trampled.
-    // TODO(dalecurtis): This is a HACK.  Long term the AudioQueue path is going
-    // away in favor of the AudioUnit based AUAudioInputStream().  Tracked by
-    // http://crbug.com/161383
-    base::TimeDelta elapsed = base::Time::Now() - last_fill_;
-    base::TimeDelta buffer_length = base::TimeDelta::FromMilliseconds(
-       audio_buffer->mAudioDataByteSize * base::Time::kMillisecondsPerSecond /
-       static_cast<float>(format_.mBytesPerFrame * format_.mSampleRate));
-    if (elapsed < buffer_length)
-      base::PlatformThread::Sleep(buffer_length - elapsed);
-
+  if (audio_buffer->mAudioDataByteSize)
     callback_->OnData(this,
                       reinterpret_cast<const uint8*>(audio_buffer->mAudioData),
                       audio_buffer->mAudioDataByteSize,
                       audio_buffer->mAudioDataByteSize,
                       0.0);
-
-    last_fill_ = base::Time::Now();
-  }
   // Recycle the buffer.
   OSStatus err = QueueNextBuffer(audio_buffer);
   if (err != noErr) {
diff --git a/media/audio/mac/audio_input_mac.h b/media/audio/mac/audio_input_mac.h
index 1f9856f1..ddef40f 100644
--- a/media/audio/mac/audio_input_mac.h
+++ b/media/audio/mac/audio_input_mac.h
@@ -9,7 +9,6 @@
 #include <AudioToolbox/AudioFormat.h>
 
 #include "base/compiler_specific.h"
-#include "base/time.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
@@ -63,7 +62,7 @@ class PCMQueueInAudioInputStream : public AudioInputStream {
                          UInt32 num_packets,
                          const AudioStreamPacketDescription* packet_desc);
 
-  static const int kNumberBuffers = 3;
+  static const int kNumberBuffers = 1;
 
   // Manager that owns this stream, used for closing down.
   AudioManagerBase* manager_;
@@ -77,8 +76,6 @@ class PCMQueueInAudioInputStream : public AudioInputStream {
   uint32 buffer_size_bytes_;
   // True iff Start() has been called successfully.
   bool started_;
-  // Used to determine if we need to slow down |callback_| calls.
-  base::Time last_fill_;
 
   DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
 };