blink fonts: Load Android SkFontMgr on Linux.

third_party/WebKit/Source/platform/fonts/linux/FontCacheLinux.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 16 matching lines @@
 #include "platform/fonts/FontPlatformData.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "public/platform/linux/WebFallbackFont.h"
 #include "public/platform/linux/WebFontInfo.h"
 #include "public/platform/linux/WebSandboxSupport.h"
 #include "public/platform/Platform.h"
 #include "wtf/text/CString.h"
 
 namespace blink {
 
+FontCache::FontCache()
+    : m_purgePreventCount(0)
+{
+    if (s_fontManager) {
+        adopted(s_fontManager);
+        m_fontManager = s_fontManager;
+    } else {
+        m_fontManager = nullptr;
+    }
+}
+
 void FontCache::getFontForCharacter(UChar32 c, const char* preferredLocale, FontCache::PlatformFallbackFont* fallbackFont)
 {
     WebFallbackFont webFallbackFont;
     if (Platform::current()->sandboxSupport())
         Platform::current()->sandboxSupport()->getFallbackFontForCharacter(c, preferredLocale, &webFallbackFont);
     else
         WebFontInfo::fallbackFontForChar(c, preferredLocale, &webFallbackFont);
     fallbackFont->name = String::fromUTF8(CString(webFallbackFont.name));
     fallbackFont->filename = webFallbackFont.filename;
     fallbackFont->fontconfigInterfaceId = webFallbackFont.fontconfigInterfaceId;
     fallbackFont->ttcIndex = webFallbackFont.ttcIndex;
     fallbackFont->isBold = webFallbackFont.isBold;
     fallbackFont->isItalic = webFallbackFont.isItalic;
 }
 
 #if !OS(ANDROID)
 PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(
     const FontDescription& fontDescription,
     UChar32 c,
     const SimpleFontData*,
     FontFallbackPriority fallbackPriority)
 {
+    // The m_fontManager is set only if it was provided by the embedder with WebFontRendering::setSkiaFontManager. This is
+    // used to emulate android fonts on linux so we always request the family from the font manager and if none is found, we return
+    // the LastResort fallback font and avoid using FontCache::getFontForCharacter which would use sandbox support to
+    // query the underlying system for the font family.
+    if (m_fontManager) {
+        AtomicString familyName = getFamilyNameForCharacter(m_fontManager.get(), c, fontDescription, fallbackPriority);
+        if (familyName.isEmpty())
+            return getLastResortFallbackFont(fontDescription, DoNotRetain);
+        return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
+    }
+
     if (fallbackPriority == FontFallbackPriority::EmojiEmoji) {
         // FIXME crbug.com/591346: We're overriding the fallback character here
         // with the FAMILY emoji in the hope to find a suitable emoji font.
         // This should be improved by supporting fallback for character
         // sequences like DIGIT ONE + COMBINING keycap etc.
         c = familyCharacter;
     }
 
     // First try the specified font with standard style & weight.
     if (fallbackPriority != FontFallbackPriority::EmojiEmoji
@@ skipping 37 matching lines @@
         return nullptr;
     FontPlatformData platformData = FontPlatformData(*substitutePlatformData);
     platformData.setSyntheticBold(shouldSetSyntheticBold);
     platformData.setSyntheticItalic(shouldSetSyntheticItalic);
     return fontDataFromFontPlatformData(&platformData, DoNotRetain);
 }
 
 #endif // !OS(ANDROID)
 
 } // namespace blink