Fix race condition in parallel font initialization.

src/ports/SkFontHost_fontconfig.cpp

 /*
  * Copyright 2008 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkFontConfigInterface.h"
 #include "SkFontConfigTypeface.h"
 #include "SkFontDescriptor.h"
@@ skipping 32 matching lines @@
 
 // convenience function to create the direct interface if none is installed.
 extern SkFontConfigInterface* SkCreateDirectFontConfigInterface();
 
 static SkFontConfigInterface* RefFCI() {
     for (;;) {
         SkFontConfigInterface* fci = SkFontConfigInterface::RefGlobal();
         if (fci) {
             return fci;
         }
-        fci = SkFontConfigInterface::GetSingletonDirectInterface();
+        fci = SkFontConfigInterface::GetSingletonDirectInterface(&gFontConfigInterfaceMutex);
         SkFontConfigInterface::SetGlobal(fci);
     }
 }
 
 // export this to SkFontMgr_fontconfig.cpp until this file just goes away.
 SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
 SkFontConfigInterface* SkFontHost_fontconfig_ref_global() {
     return RefFCI();
 }
 
@@ skipping 139 matching lines @@
         *ttcIndex = this->getIdentity().fTTCIndex;
     }
     return stream;
 }
 
 void FontConfigTypeface::onGetFontDescriptor(SkFontDescriptor* desc,
                                              bool* isLocalStream) const {
     desc->setFamilyName(this->getFamilyName());
     *isLocalStream = SkToBool(this->getLocalStream());
 }