Blink side of the change to pass the system font metrics from the browser to the renderer on Windo…

Source/platform/fonts/FontCache.h

 /*
  * Copyright (C) 2006, 2008 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2007-2008 Torch Mobile, Inc.
  *
  * 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 92 matching lines @@
 #if OS(WIN)
     bool useSubpixelPositioning() const { return s_useSubpixelPositioning; }
     SkFontMgr* fontManager() { return m_fontManager.get(); }
     static bool useDirectWrite() { return s_useDirectWrite; }
     static float deviceScaleFactor() { return s_deviceScaleFactor; }
     static void setUseDirectWrite(bool useDirectWrite) { s_useDirectWrite = useDirectWrite; }
     static void setDirectWriteFactory(IDWriteFactory* factory) { s_directWriteFactory = factory; }
     static void setDeviceScaleFactor(float deviceScaleFactor) { s_deviceScaleFactor = deviceScaleFactor; }
     static void setUseSubpixelPositioning(bool useSubpixelPositioning) { s_useSubpixelPositioning = useSubpixelPositioning; }
     static void addSideloadedFontForTesting(SkTypeface*);
+    // Functions to cache and retrieve the system font metrics.
+    static void setMenuFontMetrics(const wchar_t* familyName, int32_t fontHeight);
+    static void setSmallCaptionFontMetrics(const wchar_t* familyName, int32_t fontHeight);
+    static void setStatusFontMetrics(const wchar_t* familyName, int32_t fontHeight);
+    static int32_t menuFontHeight() { return s_menuFontHeight; }
+    static const String& menuFontFamily() { return s_smallCaptionFontFamilyName; }
+    static int32_t smallCaptionFontHeight() { return s_smallCaptionFontHeight; }
+    static const String& smallCaptionFontFamily() { return s_smallCaptionFontFamilyName; }
+    static int32_t statusFontHeight() { return s_statusFontHeight; }
+    static const String& statusFontFamily() { return s_statusFontFamilyName; }
 #endif
 
     typedef uint32_t FontFileKey;
     PassRefPtr<OpenTypeVerticalData> getVerticalData(const FontFileKey&, const FontPlatformData&);
 
 #if OS(ANDROID)
     static AtomicString getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription&);
 #else
     struct PlatformFallbackFont {
         String name;
@@ skipping 35 matching lines @@
     // Don't purge if this count is > 0;
     int m_purgePreventCount;
 
 #if OS(WIN)
     OwnPtr<SkFontMgr> m_fontManager;
     static bool s_useDirectWrite;
     static IDWriteFactory* s_directWriteFactory;
     static float s_deviceScaleFactor;
     static bool s_useSubpixelPositioning;
     static HashMap<String, RefPtr<SkTypeface> >* s_sideloadedFonts;
+    // The system font metrics cache.
+    static String s_menuFontFamilyName;

[scottmg, 2015/01/06 23:13:57]

you might need to make these String* and allocate when they're set to avoid
creating static initializers.

[ananta, 2015/01/06 23:30:16]

Makes sense. Done. Changed these to AtomicString*

+    static int32_t s_menuFontHeight;
+    static String s_smallCaptionFontFamilyName;
+    static int32_t s_smallCaptionFontHeight;
+    static String s_statusFontFamilyName;
+    static int32_t s_statusFontHeight;
 #endif
 
 #if OS(MACOSX) || OS(ANDROID)
     friend class ComplexTextController;
 #endif
     friend class SimpleFontData; // For fontDataFromFontPlatformData
     friend class FontFallbackList;
 };
 
 class PLATFORM_EXPORT FontCachePurgePreventer {
 public:
     FontCachePurgePreventer() { FontCache::fontCache()->disablePurging(); }
     ~FontCachePurgePreventer() { FontCache::fontCache()->enablePurging(); }
 };
 
 } // namespace blink
 
 #endif