Reduce jitter from uneven SincResampler buffer size requests.

media/base/audio_converter_unittest.cc

Index: media/base/audio_converter_unittest.cc
diff --git a/media/base/audio_converter_unittest.cc b/media/base/audio_converter_unittest.cc
index 0861222e5ef0eebb010479dbebee1e6cd27fe0a2..eb68db6d27c2e29c3a1e95fc118c7da36f41e44d 100644
--- a/media/base/audio_converter_unittest.cc
+++ b/media/base/audio_converter_unittest.cc
@@ -221,41 +221,51 @@ TEST(AudioConverterTest, ConvertBenchmark) {
       AudioParameters::AUDIO_PCM_LINEAR, CHANNEL_LAYOUT_MONO, 48000, 16, 2048);
   AudioParameters output_params(
       AudioParameters::AUDIO_PCM_LINEAR, CHANNEL_LAYOUT_STEREO, 44100, 16, 440);
-  scoped_ptr<AudioConverter> converter(
-      new AudioConverter(input_params, output_params, false));
-
   scoped_ptr<AudioBus> output_bus = AudioBus::Create(output_params);
-  FakeAudioRenderCallback fake_input1(0.2);
-  FakeAudioRenderCallback fake_input2(0.4);
-  FakeAudioRenderCallback fake_input3(0.6);
-  converter->AddInput(&fake_input1);
-  converter->AddInput(&fake_input2);
-  converter->AddInput(&fake_input3);
 
   printf("Benchmarking %d iterations:\n", benchmark_iterations);
 
   // Benchmark Convert() w/ FIFO.
-  base::TimeTicks start = base::TimeTicks::HighResNow();
-  for (int i = 0; i < benchmark_iterations; ++i) {
-    converter->Convert(output_bus.get());
+  {
+    scoped_ptr<AudioConverter> converter(
+        new AudioConverter(input_params, output_params, false));
+
+    FakeAudioRenderCallback fake_input1(0.2);
+    FakeAudioRenderCallback fake_input2(0.4);
+    FakeAudioRenderCallback fake_input3(0.6);
+    converter->AddInput(&fake_input1);
+    converter->AddInput(&fake_input2);
+    converter->AddInput(&fake_input3);
+
+    base::TimeTicks start = base::TimeTicks::HighResNow();
+    for (int i = 0; i < benchmark_iterations; ++i) {
+      converter->Convert(output_bus.get());
+    }
+    double total_time_ms =
+        (base::TimeTicks::HighResNow() - start).InMillisecondsF();
+    printf("Convert() w/ FIFO took %.2fms.\n", total_time_ms);
   }
-  double total_time_ms =
-      (base::TimeTicks::HighResNow() - start).InMillisecondsF();
-  printf("Convert() w/ FIFO took %.2fms.\n", total_time_ms);
-
-  converter.reset(new AudioConverter(input_params, output_params, true));
-  converter->AddInput(&fake_input1);
-  converter->AddInput(&fake_input2);
-  converter->AddInput(&fake_input3);
-
-  // Benchmark Convert() w/o FIFO.
-  start = base::TimeTicks::HighResNow();
-  for (int i = 0; i < benchmark_iterations; ++i) {
-    converter->Convert(output_bus.get());
+
+  {
+    scoped_ptr<AudioConverter> converter(
+        new AudioConverter(input_params, output_params, true));
+
+    FakeAudioRenderCallback fake_input1(0.2);
+    FakeAudioRenderCallback fake_input2(0.4);
+    FakeAudioRenderCallback fake_input3(0.6);
+    converter->AddInput(&fake_input1);
+    converter->AddInput(&fake_input2);
+    converter->AddInput(&fake_input3);
+
+    // Benchmark Convert() w/o FIFO.
+    base::TimeTicks start = base::TimeTicks::HighResNow();
+    for (int i = 0; i < benchmark_iterations; ++i) {
+      converter->Convert(output_bus.get());
+    }
+    double total_time_ms =
+        (base::TimeTicks::HighResNow() - start).InMillisecondsF();
+    printf("Convert() w/o FIFO took %.2fms.\n", total_time_ms);
   }
-  total_time_ms =
-      (base::TimeTicks::HighResNow() - start).InMillisecondsF();
-  printf("Convert() w/o FIFO took %.2fms.\n", total_time_ms);
 }
 
 TEST_P(AudioConverterTest, NoInputs) {