Adds support for capture device enumeration on Windows.

media/audio/audio_input_device_unittest.cc

Index: media/audio/audio_input_device_unittest.cc
===================================================================
--- media/audio/audio_input_device_unittest.cc	(revision 110683)
+++ media/audio/audio_input_device_unittest.cc	(working copy)
@@ -2,20 +2,60 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/environment.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/win/scoped_com_initializer.h"
 #include "media/audio/audio_manager.h"
+#if defined(OS_WIN)
+#include "media/audio/win/audio_manager_win.h"
+#endif
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace media {
+using base::win::ScopedCOMInitializer;
+using media::AudioDeviceNames;
 
+// Test fixture which allows us to override the default enumeration API on
+// Windows.
+class AudioInputDeviceTest
+    : public ::testing::Test {
+ protected:
+#if defined(OS_WIN)
+  bool SetMMDeviceEnumeration() {
+    // Windows Wave is used as default if Windows XP was detected =>
+    // return false since MMDevice is not supported on XP.
+    if (AudioManagerWin::enumeration_type() ==

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

is this stored in a global variable?

If so, won't we run into a problem when two or more that use the AudioManagerWin
class?  If one test sets the enumeration type to 'wave', then subsequent tests
will all use 'wave', right?

Instead, can we make this a regular, non-static member variable?

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

Done.

+        AudioManagerWin::kWaveEnumeration)
+      return false;

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

nit: {}  (for 3+ lines)

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

Rewriting.

+    AudioManagerWin::SetEnumerationType(AudioManagerWin::kMMDeviceEnumeration);
+      return true;

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

fix indent

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

Rewriting.

+  }
+  void SetWaveEnumeration() {
+    AudioManagerWin::SetEnumerationType(AudioManagerWin::kWaveEnumeration);
+  }
+#endif
+};
+
+// Convenience method which ensures that we are not running on the build
+// bots which lacks audio device support.
+static bool CanRunAudioTests() {
+  scoped_ptr<base::Environment> env(base::Environment::Create());
+  if (env->HasVar("CHROME_HEADLESS"))
+    return false;
+  AudioManager* audio_man = AudioManager::GetAudioManager();

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

Constructing the audio manager singleton can unfortunately have side effects and
crash other unit tests.  I have a pending changelist that allows it to be
cleaned up, but it hasn't landed yet.  Looks like we'll need to fix this problem
for the media unit tests too (not just content).

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

Agree. I will modify this test when your parts are landed.

+  return (audio_man != NULL);
+}
+
 // Test that devices can be enumerated.
-TEST(AudioInputDeviceTest, EnumerateDevices) {
+TEST_F(AudioInputDeviceTest, EnumerateDevices) {
+  if (!CanRunAudioTests())
+    return;
+  ScopedCOMInitializer com_init(ScopedCOMInitializer::kMTA);

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

maybe a note on why we use mta and not sta.

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

Done.

   AudioDeviceNames device_names;
-  ASSERT_TRUE(AudioManager::GetAudioManager() != NULL);
   AudioManager::GetAudioManager()->GetAudioInputDeviceNames(
       &device_names);
   if (!device_names.empty()) {
     AudioDeviceNames::const_iterator it = device_names.begin();
-    // The first device in the list is the prepended default device.
+    // The first device in the list should always be the default device.
     EXPECT_EQ("Default", it->device_name);
     EXPECT_EQ("0", it->unique_id);
     ++it;
@@ -29,4 +69,63 @@
   }
 }
 
-}  // namespace media
+// Run additional tests for Windows since enumeration can be done using
+// two different APIs. MMDevice is default for Vista and higher and Wave
+// is default for XP and lower.
+#if defined(OS_WIN)
+
+// Override default enumeration API and force usage of Windows MMDevice.
+// This test will only run on Windows Vista and higher.
+TEST_F(AudioInputDeviceTest, EnumerateDevicesWinMMDevice) {
+  if (!CanRunAudioTests())
+    return;
+  ScopedCOMInitializer com_init(ScopedCOMInitializer::kMTA);
+  AudioDeviceNames device_names;
+  if (!SetMMDeviceEnumeration()) {
+    // Usage of MMDevice will fail on XP and lower.
+    return;
+  }
+  AudioManager::GetAudioManager()->GetAudioInputDeviceNames(
+      &device_names);
+  if (!device_names.empty()) {
+    AudioDeviceNames::const_iterator it = device_names.begin();
+    // The first device in the list should always be the default device.
+    EXPECT_EQ("Default", it->device_name);
+    EXPECT_EQ("0", it->unique_id);
+    ++it;
+
+    // Other devices should have non-empty name and id.
+    while (it != device_names.end()) {
+      EXPECT_NE("", it->device_name);
+      EXPECT_NE("", it->unique_id);

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

should we also check that device_name is not "Default"?

+      ++it;
+    }
+  }
+}
+
+// Override default enumeration API and force usage of Windows Wave.
+// This test will run on Windows XP, Windows Vista and Windows 7.
+TEST_F(AudioInputDeviceTest, EnumerateDevicesWinWave) {
+  if (!CanRunAudioTests())
+    return;
+  AudioDeviceNames device_names;
+  SetWaveEnumeration();
+  AudioManager::GetAudioManager()->GetAudioInputDeviceNames(
+    &device_names);

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

indent

[henrika (OOO until Aug 14), 2011/11/23 09:19:19]

rewritten

+  if (!device_names.empty()) {
+    AudioDeviceNames::const_iterator it = device_names.begin();
+    // The first device in the list should always be the default device.
+    EXPECT_EQ("Default", it->device_name);
+    EXPECT_EQ("0", it->unique_id);
+    ++it;
+
+    // Other devices should have non-empty name and id.
+    while (it != device_names.end()) {
+      EXPECT_NE("", it->device_name);

[tommi (sloooow) - chröme, 2011/11/22 12:52:37]

same here.

Atually, this looks like the same exact loop as in the above test.  Factor it
out into a separate function?

+      EXPECT_NE("", it->unique_id);
+      ++it;
+    }
+  }
+}
+
+#endif