mmdevapi: Stub implement IAudioClient3.

dlls/mmdevapi/devenum.c

@@ -592,7 +592,8 @@ static HRESULT WINAPI MMDevice_Activate(IMMDevice *iface, REFIID riid, DWORD cls
         return E_POINTER;
 
     if (IsEqualIID(riid, &IID_IAudioClient) ||
-            IsEqualIID(riid, &IID_IAudioClient2)){
+            IsEqualIID(riid, &IID_IAudioClient2) ||
+            IsEqualIID(riid, &IID_IAudioClient3)){
         hr = drvs.pGetAudioEndpoint(&This->devguid, iface, (IAudioClient**)ppv);
     }else if (IsEqualIID(riid, &IID_IAudioEndpointVolume) ||
             IsEqualIID(riid, &IID_IAudioEndpointVolumeEx))

dlls/mmdevapi/tests/render.c

@@ -134,6 +134,7 @@ static void test_audioclient(void)
 {
     IAudioClient *ac;
     IAudioClient2 *ac2;
+    IAudioClient3 *ac3;
     IUnknown *unk;
     HRESULT hr;
     ULONG ref;
@@ -143,6 +144,14 @@ static void test_audioclient(void)
     BOOL offload_capable;
     AudioClientProperties client_props;
 
+    hr = IMMDevice_Activate(dev, &IID_IAudioClient3, CLSCTX_INPROC_SERVER,
+            NULL, (void**)&ac3);
+    ok(hr == S_OK ||
+            broken(hr == E_NOINTERFACE) /* win8 */,
+            "IAudioClient3 Activation failed with %08x\n", hr);
+    if(hr == S_OK)
+        IAudioClient3_Release(ac3);
+
     hr = IMMDevice_Activate(dev, &IID_IAudioClient2, CLSCTX_INPROC_SERVER,
             NULL, (void**)&ac2);
     ok(hr == S_OK, "IAudioClient2 Activation failed with %08x\n", hr);
@@ -287,6 +296,14 @@ static void test_audioclient(void)
 
     IAudioClient2_Release(ac2);
 
+    hr = IAudioClient_QueryInterface(ac, &IID_IAudioClient3, (void**)&ac3);
+    ok(hr == S_OK ||
+            broken(hr == E_NOINTERFACE) /* win8 */,
+            "Failed to query IAudioClient3 interface: %08x\n", hr);
+
+    if(hr == S_OK)
+        IAudioClient3_Release(ac3);
+
     test_uninitialized(ac);
 
     hr = IAudioClient_Initialize(ac, 3, 0, 5000000, 0, pwfx, NULL);