Add a public API to enable/disable blink runtime features by name

Source/WebKit/chromium/src/WebRuntimeFeatures.cpp

Index: Source/WebKit/chromium/src/WebRuntimeFeatures.cpp
diff --git a/Source/WebKit/chromium/src/WebRuntimeFeatures.cpp b/Source/WebKit/chromium/src/WebRuntimeFeatures.cpp
index bd951b514a74af1e89971aa5d5a0ae7f63e57a63..9084d0bcc6034fee733f96e462284445ae306e57 100644
--- a/Source/WebKit/chromium/src/WebRuntimeFeatures.cpp
+++ b/Source/WebKit/chromium/src/WebRuntimeFeatures.cpp
@@ -57,6 +57,11 @@ void WebRuntimeFeatures::enableTestOnlyFeatures(bool enable)
     RuntimeEnabledFeatures::setTestFeaturesEnabled(enable);
 }
 
+bool WebRuntimeFeatures::setFeatureEnabled(const WebString& feature, bool enable)
+{
+    return RuntimeEnabledFeatures::setFeatureEnabled(feature, enable);
+}
+
 void WebRuntimeFeatures::enableApplicationCache(bool enable)
 {
     RuntimeEnabledFeatures::setApplicationCacheEnabled(enable);