Add new entry point that supports fallback font selection based on language.

include/ports/SkTypeface_android.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkTypeface_android_DEFINED
 #define SkTypeface_android_DEFINED
 
 #include "SkTypeface.h"
 
 #ifdef SK_BUILD_FOR_ANDROID
 
 class SkPaintOptionsAndroid;
 
 /**
  *  Get the family name of the font in the fallback font list containing
- *  the specified character. if no font is found, returns false.
+ *  the specified character using the system's default language.
+ *
+ *  @param uni  The unicode character to use for the lookup.
+ *  @param name The family name of the font file containing the unicode character
+ *              in the default language
+ *  @return     true if a font is found and false otherwise
  */
 SK_API bool SkGetFallbackFamilyNameForChar(SkUnichar uni, SkString* name);
 
 /**
+ *  Get the family name of the font in the fallback font list containing
+ *  the specified character taking into account the provided language.
+ *
+ *  @param uni  The unicode character to use for the lookup.
+ *  @param lang The BCP 47 language identifier for the preferred language
+ *  @param name The family name of the font file containing the unicode character
+ *              in the preferred language
+ *  @return     true if a font is found and false otherwise
+ */
+SK_API bool SkGetFallbackFamilyNameForChar(SkUnichar uni, const SkString& lang, SkString* name);

[reed1, 2013/09/17 15:33:48]

usually we just use const char lang[] for input strings : no reason really to
require a string-object just for input.

+
+/**
  *  For test only.
  *  Load font config from given xml files, instead of those from Android system.
  */
 SK_API void SkUseTestFontConfigFile(const char* mainconf, const char* fallbackconf,
                                     const char* fontsdir);
 
 /**
  *  Given a "current" fontID, return a ref to the next logical typeface
  *  when searching fonts for a given unicode value. Typically the caller
  *  will query a given font, and if a unicode value is not supported, they
@@ skipping 28 matching lines @@
  *                   unref() when they are done.
  */
 SK_API SkTypeface* SkCreateTypefaceForScriptNG(hb_script_t script, SkTypeface::Style style,
         SkPaintOptionsAndroid::FontVariant fontVariant = SkPaintOptionsAndroid::kDefault_Variant);
 
 SK_API SkTypeface* SkCreateTypefaceForScript(HB_Script script, SkTypeface::Style style,
         SkPaintOptionsAndroid::FontVariant fontVariant = SkPaintOptionsAndroid::kDefault_Variant);
 
 #endif // #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
 #endif // #ifndef SkTypeface_android_DEFINED