Handle audio device changes on Windows.

media/audio/win/audio_device_listener_win_unittest.cc

Index: media/audio/win/audio_device_listener_win_unittest.cc
diff --git a/media/audio/win/audio_device_listener_win_unittest.cc b/media/audio/win/audio_device_listener_win_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5ef2f0cbe30fff392890633fc0259cc9e0141b4a
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+++ b/media/audio/win/audio_device_listener_win_unittest.cc
@@ -0,0 +1,89 @@
+// Copyright (c) 2012 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 <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/win/scoped_com_initializer.h"
+#include "base/utf_string_conversions.h"
+#include "media/audio/audio_manager.h"
+#include "media/audio/win/audio_device_listener_win.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using base::win::ScopedCOMInitializer;
+
+namespace media {
+
+static const char* kNoDevice = "";
+static const char* kFirstTestDevice = "test_device_0";
+static const char* kSecondTestDevice = "test_device_1";
+
+class AudioDeviceListenerWinTest
+    : public testing::Test,
+      NON_EXPORTED_BASE(public AudioManager::AudioDeviceListener) {
+ public:
+  AudioDeviceListenerWinTest()
+      : com_init_(ScopedCOMInitializer::kMTA),
+        output_device_listener_(this) {
+  }
+
+  // Simulate a device change where no output devices are available.
+  bool SimulateNullDefaultOutputDeviceChange() {
+    return output_device_listener_.OnDefaultDeviceChanged(
+        static_cast<EDataFlow>(eConsole), static_cast<ERole>(eRender),
+        NULL) == S_OK;
+  }
+
+  bool SimulateDefaultOutputDeviceChange(const char* new_device_id) {
+    return output_device_listener_.OnDefaultDeviceChanged(
+        static_cast<EDataFlow>(eConsole), static_cast<ERole>(eRender),
+        ASCIIToWide(new_device_id).c_str()) == S_OK;
+  }
+
+  void SetOutputDeviceId(std::string new_device_id) {
+    output_device_listener_.default_render_device_id_ = new_device_id;
+  }
+
+  MOCK_METHOD0(OnDeviceChange, void());
+
+ private:
+  ScopedCOMInitializer com_init_;
+  AudioDeviceListenerWin output_device_listener_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioDeviceListenerWinTest);
+};
+
+// Simulate a device change events and ensure we get the right callbacks.
+TEST_F(AudioDeviceListenerWinTest, OutputDeviceChange) {
+  SetOutputDeviceId(kNoDevice);
+  EXPECT_CALL(*this, OnDeviceChange()).Times(1);
+  ASSERT_TRUE(SimulateDefaultOutputDeviceChange(kFirstTestDevice));
+
+  testing::Mock::VerifyAndClear(this);
+  EXPECT_CALL(*this, OnDeviceChange()).Times(1);
+  ASSERT_TRUE(SimulateDefaultOutputDeviceChange(kSecondTestDevice));
+
+  // The second device event should be ignored since the device id has not
+  // changed.
+  ASSERT_TRUE(SimulateDefaultOutputDeviceChange(kSecondTestDevice));
+}
+
+// Ensure that null output device changes don't crash.  Simulates the situation
+// where we have no output devices.
+TEST_F(AudioDeviceListenerWinTest, NullOutputDeviceChange) {
+  SetOutputDeviceId(kNoDevice);
+  EXPECT_CALL(*this, OnDeviceChange()).Times(0);
+  ASSERT_TRUE(SimulateNullDefaultOutputDeviceChange());
+
+  testing::Mock::VerifyAndClear(this);
+  EXPECT_CALL(*this, OnDeviceChange()).Times(1);
+  ASSERT_TRUE(SimulateDefaultOutputDeviceChange(kFirstTestDevice));
+
+  testing::Mock::VerifyAndClear(this);
+  EXPECT_CALL(*this, OnDeviceChange()).Times(1);
+  ASSERT_TRUE(SimulateNullDefaultOutputDeviceChange());
+}
+
+}  // namespace media