Extract re-usable InitializeMediaFoundation()

media/video/capture/win/video_capture_device_factory_win.cc

 // Copyright 2014 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 "media/video/capture/win/video_capture_device_factory_win.h"
 
 #include <mfapi.h>
 #include <mferror.h>
 
 #include "base/command_line.h"
-#include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/win/metro.h"
 #include "base/win/scoped_co_mem.h"
 #include "base/win/scoped_variant.h"
 #include "base/win/windows_version.h"
 #include "media/base/media_switches.h"
+#include "media/base/win/mf_initializer.h"
 #include "media/video/capture/win/video_capture_device_mf_win.h"
 #include "media/video/capture/win/video_capture_device_win.h"
 
 using base::win::ScopedCoMem;
 using base::win::ScopedComPtr;
 using base::win::ScopedVariant;
 using Name = media::VideoCaptureDevice::Name;
 using Names = media::VideoCaptureDevice::Names;
 
 namespace media {
 
 // We would like to avoid enumerating and/or using certain devices due to they
 // provoking crashes or any other reason. This enum is defined for the purposes
 // of UMA collection. Existing entries cannot be removed.
 enum BlacklistedCameraNames {
   BLACKLISTED_CAMERA_GOOGLE_CAMERA_ADAPTER,
   BLACKLISTED_CAMERA_IP_CAMERA,
   BLACKLISTED_CAMERA_CYBERLINK_WEBCAM_SPLITTER,
    // This one must be last, and equal to the previous enumerated value.
   BLACKLISTED_CAMERA_MAX = BLACKLISTED_CAMERA_CYBERLINK_WEBCAM_SPLITTER
 };
 
-// Lazy Instance to initialize the MediaFoundation Library.
-class MFInitializerSingleton {
- public:
-  MFInitializerSingleton() { MFStartup(MF_VERSION, MFSTARTUP_LITE); }
-  ~MFInitializerSingleton() { MFShutdown(); }
-};
-
-static base::LazyInstance<MFInitializerSingleton> g_mf_initialize =
-    LAZY_INSTANCE_INITIALIZER;
-
 // Blacklisted devices are identified by a characteristic prefix of the name.
 // This prefix is used case-insensitively. This list must be kept in sync with
 // |BlacklistedCameraNames|.
 static const char* const kBlacklistedCameraNames[] = {
   // Name of a fake DirectShow filter on computers with GTalk installed.
   "Google Camera Adapter",
   // The following two software WebCams cause crashes.
   "IP Camera [JPEG/MJPEG]",
   "CyberLink Webcam Splitter",
 };
 
-static void EnsureMediaFoundationInit() {
-  g_mf_initialize.Get();
-}
-
 static bool LoadMediaFoundationDlls() {
   static const wchar_t* const kMfDLLs[] = {
     L"%WINDIR%\\system32\\mf.dll",
     L"%WINDIR%\\system32\\mfplat.dll",
     L"%WINDIR%\\system32\\mfreadwrite.dll",
   };
 
   for (int i = 0; i < arraysize(kMfDLLs); ++i) {
     wchar_t path[MAX_PATH] = {0};
     ExpandEnvironmentStringsW(kMfDLLs[i], path, arraysize(path));
     if (!LoadLibraryExW(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH))
       return false;
   }
   return true;
 }
 
 static bool PrepareVideoCaptureAttributesMediaFoundation(
     IMFAttributes** attributes,
     int count) {
-  EnsureMediaFoundationInit();
+  InitializeMediaFoundation();
 
   if (FAILED(MFCreateAttributes(attributes, count)))
     return false;
 
   return SUCCEEDED((*attributes)->SetGUID(MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
       MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID));
 }
 
 static bool CreateVideoCaptureDeviceMediaFoundation(const char* sym_link,
                                                     IMFMediaSource** source) {
@@ skipping 336 matching lines @@
 }
 
 // static
 VideoCaptureDeviceFactory*
 VideoCaptureDeviceFactory::CreateVideoCaptureDeviceFactory(
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
   return new VideoCaptureDeviceFactoryWin();
 }
 
 }  // namespace media