Add FontCache API for retrieving prioritized fallback fonts

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 591ba4f2cbf8872ef6eac5ec127e8ec2ee268ed0..361e8b927a454fc6d77ed9fb5b75fdb87c663a77 100644
--- a/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
+++ b/third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp
@@ -43,6 +43,26 @@
 #include "wtf/text/CString.h"
 #include <unicode/locid.h>
 
+#if OS(WIN)
+const char* kColorEmojiFonts[] = { "Segoe UI Emoji" };
+const char* kTextEmojiFonts[] = { "Segoe UI Symbol" };
+const char* kSymbolsFonts[] = { "Segoe UI Symbol" };
+const char* kMathFonts[] = { "Cambria Math", "Segoe UI Symbol", "Code2000" };
+#elif OS(ANDROID)
+// Due to crbug.com/322658 we cannot properly specifiy Android font family names here,

[wkorman, 2016/01/25 23:38:16]

specify

[drott, 2016/02/02 17:28:28]

Done.

+// The way Skia's SkFontMgr_android gives them canonical names, we can however
+// reference the Noto Color Emoji font under "56##fallback" on Android 6.0.1
+const char* kColorEmojiFonts[] = { "56##fallback", "Noto Color Emoji", "Android Emoji" };
+const char* kTextEmojiFonts[] = { "Droid Sans Fallback" };
+const char* kSymbolsFonts[] = { "Droid Sans Fallback" };
+const char* kMathFonts[] = { "Droid Sans Fallback" };
+#elif OS(LINUX)
+const char* kColorEmojiFonts[] = { "Noto Color Emoji", "Noto Sans Symbols", "Symbola" };
+const char* kTextEmojiFonts[] = { "Noto Sans Symbols", "Symbola" };
+const char* kSymbolsFonts[] = { "FreeSerif", "FreeMono" };
+const char* kMathFonts[] = { "FreeSerif", "FreeMono" };
+#endif
+
 #if !OS(WIN) && !OS(ANDROID)
 #include "SkFontConfigInterface.h"
 
@@ -161,6 +181,33 @@ PassRefPtr<SimpleFontData> FontCache::getLastResortFallbackFont(const FontDescri
     return fontDataFromFontPlatformData(fontPlatformData, shouldRetain);
 }
 
+
+const Vector<AtomicString> FontCache::platformFontListForFallbackPriority(FontFallbackPriority fallbackPriority) const
+{
+    Vector<AtomicString> returnVector;
+    switch (fallbackPriority) {
+    case FontFallbackPriority::EmojiEmoji:
+        for (size_t i = 0; i < WTF_ARRAY_LENGTH(kColorEmojiFonts); ++i)
+            returnVector.append(kColorEmojiFonts[i]);
+        break;
+    case FontFallbackPriority::EmojiText:
+        for (size_t i = 0; i < WTF_ARRAY_LENGTH(kTextEmojiFonts); ++i)
+            returnVector.append(kTextEmojiFonts[i]);
+        break;
+    case FontFallbackPriority::Math:
+        for (size_t i = 0; i < WTF_ARRAY_LENGTH(kMathFonts); ++i)
+            returnVector.append(kMathFonts[i]);
+        break;
+    case FontFallbackPriority::Symbols:
+        for (size_t i = 0; i < WTF_ARRAY_LENGTH(kSymbolsFonts); ++i)
+            returnVector.append(kSymbolsFonts[i]);
+        break;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    return returnVector;
+}
+
 #if OS(WIN)
 static inline SkFontStyle fontStyle(const FontDescription& fontDescription)
 {