Improved CoreAudioUtil::IsSupported()

media/audio/win/core_audio_util_win.cc

Index: media/audio/win/core_audio_util_win.cc
diff --git a/media/audio/win/core_audio_util_win.cc b/media/audio/win/core_audio_util_win.cc
index 4bae7b93f44caa3cb516935d4d69162d48e3dd4a..addf8c72f32eca4bd5daff45c0538f6937455a62 100644
--- a/media/audio/win/core_audio_util_win.cc
+++ b/media/audio/win/core_audio_util_win.cc
@@ -76,6 +76,21 @@ bool LoadAudiosesDll() {
   return (LoadLibraryExW(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH) != NULL);
 }
 
+bool CanCreateDeviceEnumerator() {
+  ScopedComPtr<IMMDeviceEnumerator> device_enumerator;
+  HRESULT hr = CoCreateInstance(__uuidof(MMDeviceEnumerator),
+                                NULL,
+                                CLSCTX_INPROC_SERVER,
+                                __uuidof(IMMDeviceEnumerator),
+                                device_enumerator.ReceiveVoid());
+
+  // If we hit CO_E_NOTINITIALIZED, CoInitialize has not been called and it
+  // must be called at least once for each thread that uses the COM library.
+  CHECK_NE(hr, CO_E_NOTINITIALIZED);
+
+  return SUCCEEDED(hr);
+}
+
 bool CoreAudioUtil::IsSupported() {
   // Microsoft does not plan to make the Core Audio APIs available for use
   // with earlier versions of Windows, including Microsoft Windows Server 2003,
@@ -90,7 +105,18 @@ bool CoreAudioUtil::IsSupported() {
   // See http://crbug.com/166397 why this extra step is required to guarantee
   // Core Audio support.
   static bool g_audioses_dll_available = LoadAudiosesDll();
-  return g_audioses_dll_available;
+  if (!g_audioses_dll_available)
+    return false;
+
+  // Being able to load the Audioses.dll does not seem to be sufficient for
+  // all devices to guarantee Core Audio support. To be 100%, we also verify
+  // that it is possible to a create the IMMDeviceEnumerator interface. If this
+  // works as well we should be home free.
+  static bool g_can_create_device_enumerator = CanCreateDeviceEnumerator();
+  LOG_IF(ERROR, !g_can_create_device_enumerator)
+      << "Failed to create Core Audio device enumerator on thread with ID "
+      << GetCurrentThreadId();
+  return g_can_create_device_enumerator;
 }
 
 base::TimeDelta CoreAudioUtil::RefererenceTimeToTimeDelta(REFERENCE_TIME time) {
@@ -141,9 +167,8 @@ ScopedComPtr<IMMDeviceEnumerator> CoreAudioUtil::CreateDeviceEnumerator() {
                                 CLSCTX_INPROC_SERVER,
                                 __uuidof(IMMDeviceEnumerator),
                                 device_enumerator.ReceiveVoid());
-  // CO_E_NOTINITIALIZED is the most likely reason for failure and if that
-  // happens we might as well die here.
-  CHECK(SUCCEEDED(hr));

[DaleCurtis, 2013/03/05 18:36:19]

I was thinking you'd keep this CHECK() since we shouldn't be hitting this code
if IsSupported() returns false.

And if we still saw CHECK() failures here we've got an even weirder problem
where CoCreateInstance eventually fails after previously succeeding.

[henrika (OOO until Aug 14), 2013/03/05 18:58:51]

I can fix that in a separate CL. OK?

+  LOG_IF(ERROR, FAILED(hr)) << "IMMDeviceEnumerator::CreateDeviceEnumerator: "
+                            << std::hex << hr;
   return device_enumerator;
 }