Make calls to AtomicString(const String&) explicit in rendering/

Source/core/rendering/RenderThemeChromiumFontProvider.cpp

Index: Source/core/rendering/RenderThemeChromiumFontProvider.cpp
diff --git a/Source/core/rendering/RenderThemeChromiumFontProvider.cpp b/Source/core/rendering/RenderThemeChromiumFontProvider.cpp
index 527f8558f78d5f2dd688b2322ef2660d0ced68ea..b8083e015fe6a5bbfde774da684954c0f309f9d0 100644
--- a/Source/core/rendering/RenderThemeChromiumFontProvider.cpp
+++ b/Source/core/rendering/RenderThemeChromiumFontProvider.cpp
@@ -46,9 +46,9 @@ float RenderThemeChromiumFontProvider::s_defaultFontSize = 16.0;
 // FIXME: The only case where we know we don't match IE is for ANSI encodings.
 // IE uses MS Shell Dlg there, which we render incorrectly at certain pixel
 // sizes (e.g. 15px). So, for now we just use Arial.
-const String& RenderThemeChromiumFontProvider::defaultGUIFont()
+const AtomicString& RenderThemeChromiumFontProvider::defaultGUIFont()
 {
-    DEFINE_STATIC_LOCAL(String, fontFace, ("Arial"));
+    DEFINE_STATIC_LOCAL(const AtomicString, fontFace, ("Arial", AtomicString::ConstructFromLiteral));
     return fontFace;
 }