Support a runtime flag for navigator content utils feature

public/web/WebRuntimeFeatures.h

Index: public/web/WebRuntimeFeatures.h
diff --git a/public/web/WebRuntimeFeatures.h b/public/web/WebRuntimeFeatures.h
index a9c293fb0227603fb92d6ed4c45485046e93bc7f..bc0f824c9686c64cb5c9776e6523dbf6bbc56bc4 100644
--- a/public/web/WebRuntimeFeatures.h
+++ b/public/web/WebRuntimeFeatures.h
@@ -137,6 +137,9 @@ public:
     WEBKIT_EXPORT static void enableHTMLImports(bool);
     WEBKIT_EXPORT static bool isHTMLImportsEnabled();
 
+    WEBKIT_EXPORT static void enableNavigatorContentUtils(bool);
+    WEBKIT_EXPORT static bool isNavigatorContentUtilsEnabled();

[abarth-chromium, 2013/08/19 19:18:07]

There's no need for this API.  We can control the feature with the generic
test/experimental/stable API.

[gyuyoung-inactive, 2013/08/20 08:24:37]

I don't understand well. Stable APIs as Geolocation, MediaStream were added to
here. Could you let me know what is difference ?

+
     WEBKIT_EXPORT static void enableCustomElements(bool);
 
     WEBKIT_EXPORT static void enableOverlayScrollbars(bool);