Add support for caching font files in the Android SkFontMgr.

src/ports/SkFontMgr_android_factory.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkTypes.h"
 #if defined(SK_BUILD_FOR_ANDROID)
 
 #include "SkFontMgr.h"
@@ skipping 18 matching lines @@
 }
 
 SkFontMgr* SkFontMgr::Factory() {
     // These globals exist so that Chromium can override the environment.
     // TODO: these globals need to be removed, and Chromium use SkFontMgr_New_Android instead.
     if ((gTestFontsXml || gTestFallbackFontsXml) && gTestBasePath) {
         SkFontMgr_Android_CustomFonts custom = {
             SkFontMgr_Android_CustomFonts::kOnlyCustom,
             gTestBasePath,
             gTestFontsXml,
-            gTestFallbackFontsXml
+            gTestFallbackFontsXml,
+            false /* fIsolated */
         };
         return SkFontMgr_New_Android(&custom);
     }
 
     return SkFontMgr_New_Android(nullptr);
 }
 
 #endif//defined(SK_BUILD_FOR_ANDROID)