Introduce AudioOutputResampler for browser side resampling.

media/base/sinc_resampler_unittest.cc

Index: media/base/sinc_resampler_unittest.cc
diff --git a/media/base/sinc_resampler_unittest.cc b/media/base/sinc_resampler_unittest.cc
index fa358e13045c82a2035070557fb0c2d793b35499..760eea561d8a7ef06f93d3021daa2e95251b0ee3 100644
--- a/media/base/sinc_resampler_unittest.cc
+++ b/media/base/sinc_resampler_unittest.cc
@@ -58,6 +58,36 @@ TEST(SincResamplerTest, ChunkedResample) {
   resampler.Resample(resampled_destination.get(), max_chunk_size);
 }
 
+// Test flush resets the internal state properly.
+TEST(SincResamplerTest, Flush) {
+  MockSource mock_source;
+  SincResampler resampler(
+      kSampleRateRatio,
+      base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
+  scoped_array<float> resampled_destination(new float[resampler.ChunkSize()]);
+
+  EXPECT_CALL(mock_source, ProvideInput(_, _)).Times(1);
+  resampler.Resample(resampled_destination.get(), resampler.ChunkSize());
+
+  // Figure out buffer size from internal buffer layout.
+  int buffer_size_float = reinterpret_cast<int>(
+      resampler.r4_ + (resampler.r4_ - resampler.r3_) - resampler.r1_);

[scherkus (not reviewing), 2012/09/07 13:30:17]

instead of friend test + poking around internals, perhaps we can add some
xxx_for_test() / XxxForTest() methods on SinceResampler that does some of this
work for us?

[DaleCurtis, 2012/09/07 14:17:35]

I like this idea. Will change.

[DaleCurtis, 2012/09/10 12:06:24]

Found a better way => Prime with junk data, Flush(), ensure correct results.

+  int buffer_size_bytes = buffer_size_float * sizeof(*(

[scherkus (not reviewing), 2012/09/07 13:30:17]

looks bizarre -- drop sizeof to next line?

[DaleCurtis, 2012/09/10 12:06:24]

Removed.

+      resampler.input_buffer_.get()));
+
+  // Fill input buffer with junk data so we can if it's cleared afterwards.
+  memset(resampler.input_buffer_.get(), 0xFF, buffer_size_bytes);
+
+  EXPECT_TRUE(resampler.buffer_primed_);
+  EXPECT_NE(resampler.virtual_source_idx_, 0);
+
+  resampler.Flush();
+  EXPECT_FALSE(resampler.buffer_primed_);
+  EXPECT_EQ(resampler.virtual_source_idx_, 0);
+  for (int i = 0; i < buffer_size_float; ++i)
+    ASSERT_FLOAT_EQ(resampler.input_buffer_.get()[i], 0);
+}
+
 // Ensure various optimized Convolve() methods return the same value.  Only run
 // this test if other optimized methods exist, otherwise the default Convolve()
 // will be tested by the parameterized SincResampler tests below.