Initialize the SkFontConfigInterface singleton with SkOnce.

src/ports/SkFontConfigInterface_direct.cpp

 /*
  * Copyright 2009 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* migrated from chrome/src/skia/ext/SkFontHost_fontconfig_direct.cpp */
 
 #include <string>
 #include <unistd.h>
 #include <fcntl.h>
 
 #include <fontconfig/fontconfig.h>
 
 #include "SkBuffer.h"
 #include "SkFontConfigInterface.h"
+#include "SkOnce.h"
 #include "SkStream.h"
 
 size_t SkFontConfigInterface::FontIdentity::writeToMemory(void* addr) const {
     size_t size = sizeof(fID) + sizeof(fTTCIndex);
     size += sizeof(int32_t) + sizeof(int32_t) + sizeof(uint8_t); // weight, width, italic
     size += sizeof(int32_t) + fString.size();    // store length+data
     if (addr) {
         SkWBuffer buffer(addr, size);
 
         buffer.write32(fID);
@@ skipping 88 matching lines @@
     // new APIs
     virtual SkDataTable* getFamilyNames() SK_OVERRIDE;
     virtual bool matchFamilySet(const char inFamilyName[],
                                 SkString* outFamilyName,
                                 SkTArray<FontIdentity>*) SK_OVERRIDE;
 
 private:
     SkMutex mutex_;
 };
 
+static void create_singleton_direct_interface(SkFontConfigInterface** singleton) {
+    *singleton = new SkFontConfigInterfaceDirect;
+}
 SkFontConfigInterface* SkFontConfigInterface::GetSingletonDirectInterface() {
     static SkFontConfigInterface* gDirect;
-    if (NULL == gDirect) {
-        static SkMutex gMutex;
-        SkAutoMutexAcquire ac(gMutex);
-
-        if (NULL == gDirect) {
-            gDirect = new SkFontConfigInterfaceDirect;
-        }
-    }
+    SK_DECLARE_STATIC_ONCE(once);
+    SkOnce(&once, create_singleton_direct_interface, &gDirect);
     return gDirect;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 // Returns the string from the pattern, or NULL
 static const char* get_name(FcPattern* pattern, const char field[],
                             int index = 0) {
     const char* name;
     if (FcPatternGetString(pattern, field, index,
@@ skipping 581 matching lines @@
                 *trimmedMatches.append() = match[i];
             }
         }
 
         SkFontStyleSet_FC* sset = SkNEW_ARGS(SkFontStyleSet_FC,
                                              (trimmedMatches.begin(),
                                               trimmedMatches.count()));
 #endif
     return false;
 }