Use CSS value instead of serialized string in CanvasRenderingContext2D::setFont

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index ad626b2ac61dbe69366729cc585de45edfb25b38..892723a84d7e03de947b86e7310c57d4535a3b16 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -79,7 +79,6 @@ static const int defaultFontSize = 10;
 static const char defaultFontFamily[] = "sans-serif";
 static const char defaultFont[] = "10px sans-serif";
 static const char inherit[] = "inherit";
-static const char initial[] = "initial";
 static const char rtl[] = "rtl";
 static const char ltr[] = "ltr";
 static const double TryRestoreContextInterval = 0.5;
@@ -1682,10 +1681,10 @@ void CanvasRenderingContext2D::setFont(const String& newFont)
         }
         if (parsedStyle->isEmpty())
             return;
-        String fontValue = parsedStyle->getPropertyValue(CSSPropertyFont);
         // According to http://lists.w3.org/Archives/Public/public-html/2009Jul/0947.html,
         // the "inherit" and "initial" values must be ignored.
-        if (fontValue == inherit || fontValue == initial)
+        RefPtrWillBeRawPtr<CSSValue> fontValue = parsedStyle->getPropertyCSSValue(CSSPropertyFontSize);
+        if (fontValue && (fontValue->isInitialValue() || fontValue->isInheritedValue()))
             return;
         m_fetchedFonts.add(newFont, parsedStyle);
     }