Enabled mono playback support for Linux.

media/audio/linux/alsa_output_unittest.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/logging.h"
 #include "media/audio/linux/alsa_output.h"
 #include "media/audio/linux/alsa_wrapper.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 90 matching lines @@
     AlsaPcmOutputStreamTest::kTestFramesPerPacket *
     AlsaPcmOutputStreamTest::kTestBytesPerFrame;
 const int AlsaPcmOutputStreamTest::kTestFailedErrno = -EACCES;
 snd_pcm_t* const AlsaPcmOutputStreamTest::kFakeHandle =
     reinterpret_cast<snd_pcm_t*>(1);
 
 TEST_F(AlsaPcmOutputStreamTest, ConstructedState) {
   EXPECT_EQ(AlsaPcmOutputStream::kCreated,
             test_stream_->shared_data_.state());
 
-  // Only supports 2 channel.
+  // Should support mono.
   test_stream_ = new AlsaPcmOutputStream(kTestDeviceName,
                                          kTestFormat,
-                                         kTestChannels + 1,
+                                         1,  // Channels.
                                          kTestSampleRate,
                                          kTestBitsPerSample,
                                          &mock_alsa_wrapper_,
+                                         &message_loop_);
+  EXPECT_EQ(AlsaPcmOutputStream::kCreated,
+            test_stream_->shared_data_.state());
+
+  // Should not support multi-channel.
+  test_stream_ = new AlsaPcmOutputStream(kTestDeviceName,
+                                         kTestFormat,
+                                         3,  // Channels.
+                                         kTestSampleRate,
+                                         kTestBitsPerSample,
+                                         &mock_alsa_wrapper_,
                                          &message_loop_);
   EXPECT_EQ(AlsaPcmOutputStream::kInError,
             test_stream_->shared_data_.state());
 
   // Bad bits per sample.
   test_stream_ = new AlsaPcmOutputStream(kTestDeviceName,
                                          kTestFormat,
                                          kTestChannels,
                                          kTestSampleRate,
                                          kTestBitsPerSample - 1,
@@ skipping 242 matching lines @@
 
   test_stream_->stop_stream_ = true;
   test_stream_->ScheduleNextWrite(&packet_);
 
   // TODO(ajwong): Find a way to test whether or not another task has been
   // posted so we can verify that the Alsa code will indeed break the task
   // posting loop.
 
   test_stream_->shared_data_.TransitionTo(AlsaPcmOutputStream::kIsClosed);
 }