Introduce DEFINE_CUSTOM_FONT_DATA_TYPE_CASTS, and use it

Source/platform/fonts/CustomFontData.h

Index: Source/platform/fonts/CustomFontData.h
diff --git a/Source/platform/fonts/CustomFontData.h b/Source/platform/fonts/CustomFontData.h
index d15c2b2c10b44cd612ac933e6b1a3a47e3db4fdc..b281342ddeb1ee7bd1f91d642806401878c4a1bd 100644
--- a/Source/platform/fonts/CustomFontData.h
+++ b/Source/platform/fonts/CustomFontData.h
@@ -56,6 +56,10 @@ protected:
     CustomFontData() { }
 };
 
+#define DEFINE_CUSTOM_FONT_DATA_TYPE_CASTS(thisType, predicate) \

[tkent, 2014/08/11 01:04:56]

I feel introducing new macro only for SVGFontData is overkill.  But it's ok.

[gyuyoung-inactive, 2014/08/11 04:50:55]

If there is only SVGFontData as child class of CustomFontData class, I didn't
use this. But, there are two more child classes(CSSCustomFontData and
TestCustomFontData) though they don't use type casting yet. So, I add new macro
so that those classes also will use this macro in future.

+    template<typename T> inline thisType* to##thisType(const RefPtr<T>& customFontData) { return to##thisType(customFontData.get()); } \
+    DEFINE_TYPE_CASTS(thisType, CustomFontData, customFontData, customFontData->predicate, customFontData.predicate)
+
 }
 
 #endif // CustomFontData_h