More LayoutLocale refactor with additional Chinese support

third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp

Index: third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
diff --git a/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp b/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
index 7cb8c5cfac687d8444dd1c689a07e47a4fabcd5d..af11f0f2910833251c9a5036d69edd370690ba9e 100644
--- a/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
+++ b/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
@@ -32,7 +32,6 @@
 #include "SkStream.h"
 #include "SkTypeface.h"
 #include "platform/Language.h"
-#include "platform/fonts/AcceptLanguagesResolver.h"
 #include "platform/fonts/AlternateFontFamily.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/FontDescription.h"
@@ -81,14 +80,16 @@ AtomicString FontCache::getFamilyNameForCharacter(SkFontMgr* fm, UChar32 c, cons
     const char* bcp47Locales[kMaxLocales];
     size_t localeCount = 0;
 
-    if (fallbackPriority == FontFallbackPriority::EmojiEmoji) {
+    // Fill in the list of locales in the reverse priority order.
+    // The last one is the highest.

[drott, 2016/07/28 08:05:23]

Perhaps we can rephrase this second line of the comment: Skia expects the
highest array index to be the first priority.

Makes sense to include this change.

Did you test this with mixed text-presentation and emoji-presentation pages on
Android?

[kojii, 2016/07/29 04:27:40]

Your text looks great, fixed. Wanted to put a link to Skia documents but it
looks like there doesn't exist...
Tested a few pages on a real device and see no differences.
http://unicode.org/emoji/charts/emoji-zwj-sequences.html
http://apps.timwhitlock.info/emoji/tables/unicode

I now remember we don't run most of LayoutTests on Android. Probably we should
have gtest or make a LayoutTest runnable on Linux that differentiate this line,
but I know it's a bit tricky to build such a test.

At least changing the order doesn't break major cases, and logically this is the
right fix, as we add content locale after the default locale.

+    const LayoutLocale* contentLocale = fontDescription.locale();
+    if (const LayoutLocale* hanLocale = LayoutLocale::localeForHan(contentLocale))
+        bcp47Locales[localeCount++] = hanLocale->localeForHanForSkFontMgr();
+    bcp47Locales[localeCount++] = LayoutLocale::getDefault().localeForSkFontMgr();
+    if (contentLocale)
+        bcp47Locales[localeCount++] = contentLocale->localeForSkFontMgr();
+    if (fallbackPriority == FontFallbackPriority::EmojiEmoji)
         bcp47Locales[localeCount++] = kAndroidColorEmojiLocale;
-    }
-    if (const char* hanLocale = AcceptLanguagesResolver::preferredHanSkFontMgrLocale())
-        bcp47Locales[localeCount++] = hanLocale;
-    bcp47Locales[localeCount++] = LayoutLocale::getDefault().localeForSkFontMgr().data();
-    if (const LayoutLocale* locale = fontDescription.locale())
-        bcp47Locales[localeCount++] = locale->localeForSkFontMgr().data();
     ASSERT_WITH_SECURITY_IMPLICATION(localeCount < kMaxLocales);
     RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
     if (!typeface)