Make the use of fallback fonts in Android a runtime decision.

src/ports/SkFontHost_android.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkFontHost.h"
 #include "SkFontHost_FreeType_common.h"
 #include "SkFontDescriptor.h"
@@ skipping 785 matching lines @@
         tf = find_best_face(gDefaultFamily, style);
     }
 
     // we ref(), since the semantic is to return a new instance
     tf->ref();
     return tf;
 }
 
 SkTypeface* SkAndroidNextLogicalTypeface(SkFontID currFontID, SkFontID origFontID,
                                          const SkPaintOptionsAndroid& options) {
-#if !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
-    // Skia does not support font fallback for ndk applications in order to
-    // enable clients such as WebKit to customize their font selection.
-    // Clients can use GetFallbackFamilyNameForChar() to get the fallback
+    // Skia does not support font fallback by default for ndk applications. This
+    // enables clients such as WebKit to customize their font selection. In any
+    // case clients can use GetFallbackFamilyNameForChar() to get the fallback
     // font for individual characters.
-    return NULL;
-#endif
+    if (!options.isUsingFontFallbacks()) {
+        return NULL;
+    }
+
     SkAutoMutexAcquire  ac(gFamilyHeadAndNameListMutex);
 
     load_system_fonts();
 
     const SkTypeface* origTypeface = find_from_uniqueID(origFontID);
     const SkTypeface* currTypeface = find_from_uniqueID(currFontID);
 
     SkASSERT(origTypeface != 0);
     SkASSERT(currTypeface != 0);
     SkASSERT(gFallbackFonts);
@@ skipping 111 matching lines @@
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "SkFontMgr.h"
 
 SkFontMgr* SkFontMgr::Factory() {
     // todo
     return NULL;
 }