Allow the default generic font family settings to find the first available font

third_party/WebKit/Source/platform/fonts/FontCache.cpp

 /*
  * Copyright (C) 2006, 2008 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 30 matching lines @@
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontPlatformData.h"
 #include "platform/fonts/FontSmoothingMode.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "platform/fonts/TextRenderingMode.h"
 #include "platform/fonts/opentype/OpenTypeVerticalData.h"
 #include "platform/fonts/shaping/ShapeCache.h"
 #include "platform/tracing/web_memory_allocator_dump.h"
 #include "platform/tracing/web_process_memory_dump.h"
 #include "public/platform/Platform.h"
+#include "ui/gfx/font.h"
 #include "wtf/HashMap.h"
 #include "wtf/ListHashSet.h"
 #include "wtf/PtrUtil.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/Vector.h"
 #include "wtf/text/AtomicStringHash.h"
 #include "wtf/text/StringHash.h"
 #include <memory>
 
 using namespace WTF;
@@ skipping 234 matching lines @@
 }
 
 bool FontCache::isPlatformFontAvailable(const FontDescription& fontDescription,
                                         const AtomicString& family) {
   bool checkingAlternateName = true;
   return getFontPlatformData(
       fontDescription,
       FontFaceCreationParams(adjustFamilyNameToAvoidUnsupportedFonts(family)),
       checkingAlternateName);
 }
+static bool isFontFamilyAvailable(const String& family,
+                                  SkFontMgr* fontManager) {
+#if OS(LINUX)
+  sk_sp<SkTypeface> typeface(
+      fontManager->legacyCreateTypeface(family.utf8().data(), SkFontStyle()));
+  return typeface;
+#else
+  sk_sp<SkFontStyleSet> set(fontManager->matchFamily(family.utf8().data()));
+  return set && set->count();
+#endif
+}
+
+String FontCache::firstAvailableOrFirst(const String& families) {
+  Vector<String> familyList;
+  families.split(',', familyList);
+  if (familyList.isEmpty())
+    return String();
+  sk_sp<SkFontMgr> fm(SkFontMgr::RefDefault());
+  for (String& family : familyList) {
+    family = family.stripWhiteSpace();
+    if (isFontFamilyAvailable(family, fm.get()))
+      return family;
+  }
+  return familyList.first();
+}
 
 SimpleFontData* FontCache::getNonRetainedLastResortFallbackFont(
     const FontDescription& fontDescription) {
   return getLastResortFallbackFont(fontDescription, DoNotRetain).leakRef();
 }
 
 void FontCache::releaseFontData(const SimpleFontData* fontData) {
   ASSERT(gFontDataCache);
 
   gFontDataCache->release(fontData);
@@ skipping 159 matching lines @@
   for (iter = gFallbackListShaperCache->begin();
        iter != gFallbackListShaperCache->end(); ++iter) {
     shapeResultCacheSize += iter->value->byteSize();
   }
   dump->AddScalar("size", "bytes", shapeResultCacheSize);
   memoryDump->AddSuballocation(dump->guid(),
                                WTF::Partitions::kAllocatedObjectPoolName);
 }
 
 }  // namespace blink