Match language tags by prefix on Android.

src/ports/SkFontMgr_android.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 "SkFontConfigParser_android.h"
 #include "SkFontDescriptor.h"
 #include "SkFontHost_FreeType_common.h"
@@ skipping 335 matching lines @@
 
 static SkTypeface_AndroidSystem* find_family_style_character(
         const SkTDArray<NameToFamily>& fallbackNameToFamilyMap,
         const SkFontStyle& style, bool elegant,
         const SkString& langTag, SkUnichar character)
 {
     for (int i = 0; i < fallbackNameToFamilyMap.count(); ++i) {
         SkFontStyleSet_Android* family = fallbackNameToFamilyMap[i].styleSet;
         SkAutoTUnref<SkTypeface_AndroidSystem> face(family->matchStyle(style));
 
-        if (!langTag.isEmpty() && langTag != face->fLang.getTag()) {
+        if (!langTag.isEmpty() && !face->fLang.getTag().startsWith(langTag.c_str())) {
             continue;
         }
 
         if (SkToBool(face->fVariantStyle & kElegant_FontVariant) != elegant) {
             continue;
         }
 
         SkPaint paint;
         paint.setTypeface(face);
         paint.setTextEncoding(SkPaint::kUTF32_TextEncoding);
@@ skipping 185 matching lines @@
     SkDEBUGF(("Use Test Config File Main %s, Fallback %s, Font Dir %s",
               gTestMainConfigFile, gTestFallbackConfigFile, gTestFontFilePrefix));
 }
 
 void SkGetTestFontConfiguration(const char** mainconf, const char** fallbackconf,
                                 const char** fontsdir) {
     *mainconf = gTestMainConfigFile;
     *fallbackconf = gTestFallbackConfigFile;
     *fontsdir = gTestFontFilePrefix;
 }