Introduce AudioOutputResampler for browser side resampling.

media/base/audio_fifo.cc

Index: media/base/audio_fifo.cc
diff --git a/media/base/audio_fifo.cc b/media/base/audio_fifo.cc
index 87a5d823c41b2c11aef41ae376bf5709fc3febbd..ded104426bb62199064e698fcbfbcdce7190c11c 100644
--- a/media/base/audio_fifo.cc
+++ b/media/base/audio_fifo.cc
@@ -35,12 +35,12 @@ AudioFifo::AudioFifo(int channels, int frames)
 
 AudioFifo::~AudioFifo() {}
 
-bool AudioFifo::Push(const AudioBus* source) {
+bool AudioFifo::Push(const AudioBus* source, int frames) {
   DCHECK(source);
   DCHECK_EQ(source->channels(), audio_bus_->channels());
 
   // Ensure that there is space for the new data in the FIFO.
-  const int source_size = source->frames();
+  const int source_size = frames;
   if (frames_in_fifo_ + source_size > max_frames()) {
     DLOG(ERROR) << "FIFO overflow.";
     return false;
@@ -71,7 +71,8 @@ bool AudioFifo::Push(const AudioBus* source) {
   return true;
 }
 
-bool AudioFifo::Consume(AudioBus* destination, int frames_to_consume) {
+bool AudioFifo::Consume(AudioBus* destination, int start_frame,
+                        int frames_to_consume) {
   DCHECK(destination);
   DCHECK_EQ(destination->channels(), audio_bus_->channels());
 
@@ -83,8 +84,8 @@ bool AudioFifo::Consume(AudioBus* destination, int frames_to_consume) {
 
   // A copy from the FIFO to |destination| will only be performed if the
   // allocated memory in |destination| is sufficient.
-  if (frames_to_consume > destination->frames()) {
-    DLOG(ERROR) << "Insufficient space in destination.";
+  if (frames_to_consume + start_frame > destination->frames()) {
+    LOG(ERROR) << "Insufficient space in destination.";
     return false;
   }
 
@@ -102,10 +103,11 @@ bool AudioFifo::Consume(AudioBus* destination, int frames_to_consume) {
     const float* src = audio_bus_->channel(ch);
 
     // Copy a selected part of the FIFO to the destination.
-    memcpy(&dest[0], &src[read_pos_], consume_size * sizeof(src[0]));
+    memcpy(&dest[start_frame], &src[read_pos_], consume_size * sizeof(src[0]));
     if (wrap_size > 0) {
       // Wrapping is needed: copy remaining part to the destination.
-      memcpy(&dest[consume_size], &src[0], wrap_size * sizeof(src[0]));
+      memcpy(&dest[consume_size + start_frame], &src[0],
+             wrap_size * sizeof(src[0]));
     }
   }