Extend FontCache fallback API to support FontFallbackPriority

third_party/WebKit/Source/platform/fonts/mac/FontCacheMac.mm

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 35 matching lines @@
 
 // Forward declare Mac SPIs.
 // Request for public API: rdar://13803570
 @interface NSFont (WebKitSPI)
 + (NSFont*)findFontLike:(NSFont*)font forString:(NSString*)string withRange:(NSRange)range inLanguage:(id)useNil;
 + (NSFont*)findFontLike:(NSFont*)font forCharacter:(UniChar)uc inLanguage:(id)useNil;
 @end
 
 namespace blink {
 
+const char* kColorEmojiFontMac = "Apple Color Emoji";
+
 static void invalidateFontCache()
 {
     if (!isMainThread()) {
         Platform::current()->mainThread()->taskRunner()->postTask(BLINK_FROM_HERE, bind(&invalidateFontCache));
         return;
     }
     FontCache::fontCache()->invalidate();
 }
 
 static void fontCacheRegisteredFontsChangedNotificationCallback(CFNotificationCenterRef, void* observer, CFStringRef name, const void *, CFDictionaryRef)
@@ skipping 14 matching lines @@
 void FontCache::platformInit()
 {
     CFNotificationCenterAddObserver(CFNotificationCenterGetLocalCenter(), this, fontCacheRegisteredFontsChangedNotificationCallback, kCTFontManagerRegisteredFontsChangedNotification, 0, CFNotificationSuspensionBehaviorDeliverImmediately);
 }
 
 static inline bool isAppKitFontWeightBold(NSInteger appKitFontWeight)
 {
     return appKitFontWeight >= 7;
 }
 
-PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 character, const SimpleFontData* fontDataToSubstitute)
+PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(
+    const FontDescription& fontDescription,
+    UChar32 character,
+    const SimpleFontData* fontDataToSubstitute,
+    FontFallbackPriority fallbackPriority)
 {
+
+    if (fallbackPriority == FontFallbackPriority::EmojiEmoji) {
+        RefPtr<SimpleFontData> emojiFont = getFontData(fontDescription, AtomicString(kColorEmojiFontMac));
+        if (emojiFont)
+            return emojiFont;
+    }
+
     // FIXME: We should fix getFallbackFamily to take a UChar32
     // and remove this split-to-UChar16 code.
     UChar codeUnits[2];
     int codeUnitsLength;
     if (character <= 0xFFFF) {
         codeUnits[0] = character;
         codeUnitsLength = 1;
     } else {
         codeUnits[0] = U16_LEAD(character);
         codeUnits[1] = U16_TRAIL(character);
@@ skipping 119 matching lines @@
     // When loading fails, we do not want to use the returned FontPlatformData since it will not have
     // a valid SkTypeface.
     OwnPtr<FontPlatformData> platformData = adoptPtr(new FontPlatformData(platformFont, size, syntheticBold, syntheticItalic, fontDescription.orientation()));
     if (!platformData->typeface()) {
         return nullptr;
     }
     return platformData.release();
 }
 
 } // namespace blink