Clean up SkOnce:

src/utils/win/SkDWrite.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDWrite.h"
 #include "SkHRESULT.h"
 #include "SkOnce.h"
 #include "SkString.h"
 
 #include <dwrite.h>
 
 static IDWriteFactory* gDWriteFactory = NULL;
 
+static void release_dwrite_factory() {
+    if (gDWriteFactory) {
+        gDWriteFactory->Release();
+    }
+}
+
 static void create_dwrite_factory(IDWriteFactory** factory) {
     typedef decltype(DWriteCreateFactory)* DWriteCreateFactoryProc;
     DWriteCreateFactoryProc dWriteCreateFactoryProc = reinterpret_cast<DWriteCreateFactoryProc>(
         GetProcAddress(LoadLibraryW(L"dwrite.dll"), "DWriteCreateFactory"));
 
     if (!dWriteCreateFactoryProc) {
         HRESULT hr = HRESULT_FROM_WIN32(GetLastError());
         if (!IS_ERROR(hr)) {
             hr = ERROR_PROC_NOT_FOUND;
         }
         HRVM(hr, "Could not get DWriteCreateFactory proc.");
     }
 
     HRVM(dWriteCreateFactoryProc(DWRITE_FACTORY_TYPE_SHARED,
                                  __uuidof(IDWriteFactory),
                                  reinterpret_cast<IUnknown**>(factory)),
          "Could not create DirectWrite factory.");
+    atexit(release_dwrite_factory);
 }
 
-static void release_dwrite_factory() {
-    if (gDWriteFactory) {
-        gDWriteFactory->Release();
-    }
-}
 
 IDWriteFactory* sk_get_dwrite_factory() {
     SK_DECLARE_STATIC_ONCE(once);
-    SkOnce(&once, create_dwrite_factory, &gDWriteFactory, release_dwrite_factory);
+    SkOnce(&once, create_dwrite_factory, &gDWriteFactory);
 
     return gDWriteFactory;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // String conversion
 
 /** Converts a utf8 string to a WCHAR string. */
 HRESULT sk_cstring_to_wchar(const char* skname, SkSMallocWCHAR* name) {
     int wlen = MultiByteToWideChar(CP_UTF8, 0, skname, -1, NULL, 0);
@@ skipping 64 matching lines @@
     );
     if (!*proc) {
         HRESULT hr = HRESULT_FROM_WIN32(GetLastError());
         if (!IS_ERROR(hr)) {
             hr = ERROR_PROC_NOT_FOUND;
         }
         return hr;
     }
     return S_OK;
 }