Extract re-usable InitializeMediaFoundation()

Allow media::InitializeMediaFoundation() to be used by any Media
Foundation client code.  This benefits existing Chromium code as well as any
Chromium-based browser that adds its own code calling out to Media Foundation.

There are two side effects for DXVAVideoDecodeAccelerator:

  - MFStartup() and MFShutdown() are now called once during the lifetime of the
    GPU process rather than per each accelerator instance.

  - MFStartup() is now called with the MFSTARTUP_LITE flag, which according to
    MSDN doesn't initialize the sockets library.

TEST=media_unittests

Review URL: https://codereview.chromium.org/1149203002

Cr-Commit-Position: refs/heads/master@{#331446}

1 files changed, 2 insertions, 16 deletions

diff --git a/media/video/capture/win/video_capture_device_factory_win.cc b/media/video/capture/win/video_capture_device_factory_win.cc
index 7f0d665..8b018fb 100644
--- a/media/video/capture/win/video_capture_device_factory_win.cc
+++ b/media/video/capture/win/video_capture_device_factory_win.cc
@@ -8,7 +8,6 @@
 #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"
@@ -17,6 +16,7 @@
 #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"
 
@@ -39,16 +39,6 @@ enum BlacklistedCameraNames {
   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|.
@@ -60,10 +50,6 @@ static const char* const kBlacklistedCameraNames[] = {
   "CyberLink Webcam Splitter",
 };
 
-static void EnsureMediaFoundationInit() {
-  g_mf_initialize.Get();
-}
-
 static bool LoadMediaFoundationDlls() {
   static const wchar_t* const kMfDLLs[] = {
     L"%WINDIR%\\system32\\mf.dll",
@@ -83,7 +69,7 @@ static bool LoadMediaFoundationDlls() {
 static bool PrepareVideoCaptureAttributesMediaFoundation(
     IMFAttributes** attributes,
     int count) {
-  EnsureMediaFoundationInit();
+  InitializeMediaFoundation();
 
   if (FAILED(MFCreateAttributes(attributes, count)))
     return false;