Allow default font size changing on Linux.

Source/web/linux/WebFontRendering.cpp

Index: Source/web/linux/WebFontRendering.cpp
diff --git a/Source/web/linux/WebFontRendering.cpp b/Source/web/linux/WebFontRendering.cpp
index 86107b974c28c3546cd0926f628cede8ded97945..11f455bb8a0a7f621f941addaef96df6d548e16f 100644
--- a/Source/web/linux/WebFontRendering.cpp
+++ b/Source/web/linux/WebFontRendering.cpp
@@ -31,6 +31,7 @@
 #include "config.h"
 #include "public/web/linux/WebFontRendering.h"
 
+#include "core/rendering/RenderThemeChromiumFontProvider.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontPlatformData.h"
 
@@ -87,4 +88,10 @@ void WebFontRendering::setLCDOrientation(SkFontHost::LCDOrientation orientation)
     SkFontHost::SetSubpixelOrientation(orientation);
 }
 
+// static
+void WebFontRendering::setDefaultFontSize(int size)
+{
+    RenderThemeChromiumFontProvider::setDefaultFontSize(size);
+}
+
 } // namespace blink