Use larger buffer sizes for lower power on Linux.

media/audio/pulse/audio_manager_pulse.cc

Index: media/audio/pulse/audio_manager_pulse.cc
diff --git a/media/audio/pulse/audio_manager_pulse.cc b/media/audio/pulse/audio_manager_pulse.cc
index 3369fd5a05be40228affaee5d744172b35ada708..238530a2038a6d8b904c62af0dd0ef2097bdccf6 100644
--- a/media/audio/pulse/audio_manager_pulse.cc
+++ b/media/audio/pulse/audio_manager_pulse.cc
@@ -35,6 +35,10 @@ using pulse::WaitForOperationCompletion;
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
+// Define bounds for the output buffer size.
+static const int kMinimumOutputBufferSize = 512;
+static const int kMaximumOutputBufferSize = 8192;
+
 static const base::FilePath::CharType kPulseLib[] =
     FILE_PATH_LITERAL("libpulse.so.0");
 
@@ -161,10 +165,9 @@ AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
     const AudioParameters& input_params) {
   // TODO(tommi): Support |output_device_id|.
   VLOG_IF(0, !output_device_id.empty()) << "Not implemented!";
-  static const int kDefaultOutputBufferSize = 512;
 
   ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
-  int buffer_size = kDefaultOutputBufferSize;
+  int buffer_size = kMinimumOutputBufferSize;
   int bits_per_sample = 16;
   int input_channels = 0;
   int sample_rate;
@@ -172,7 +175,9 @@ AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
     bits_per_sample = input_params.bits_per_sample();
     channel_layout = input_params.channel_layout();
     input_channels = input_params.input_channels();
-    buffer_size = std::min(buffer_size, input_params.frames_per_buffer());
+    buffer_size =
+        std::min(kMaximumOutputBufferSize,
+                 std::max(buffer_size, input_params.frames_per_buffer()));
     sample_rate = input_params.sample_rate();
   } else {
     sample_rate = GetNativeSampleRate();