Use std::string instead of WebString in WebRuntimeFeatures

public/web/WebRuntimeFeatures.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebRuntimeFeatures_h
 #define WebRuntimeFeatures_h
 
 #include "../platform/WebCommon.h"
 #include "../platform/WebString.h"
 
+#include <string>
+
 namespace blink {
 
 // This class is used to enable runtime features of Blink.
 // Stable features are enabled by default.
 class WebRuntimeFeatures {
 public:
     BLINK_EXPORT static void enableExperimentalFeatures(bool);
 
     BLINK_EXPORT static void enableWebBluetooth(bool);
 
     BLINK_EXPORT static void enableTestOnlyFeatures(bool);
 
     // Enables a feature by its string identifier from
     // RuntimeEnabledFeatures.in.
+    // Note: We use std::string instead of WebString because this API can
+    // be called before blink::initalize(). We can't create WebString objects
+    // before blink::initialize().
+    BLINK_EXPORT static void enableFeatureFromString(const std::string& name, bool enable);
+    // TODO(bashi): Remove.
     BLINK_EXPORT static void enableFeatureFromString(const WebString& name, bool enable);
 
     BLINK_EXPORT static void enableApplicationCache(bool);
 
     BLINK_EXPORT static void enableDatabase(bool);
 
     BLINK_EXPORT static void enableCompositedSelectionUpdate(bool);
     BLINK_EXPORT static bool isCompositedSelectionUpdateEnabled();
 
     BLINK_EXPORT static void enableDecodeToYUV(bool);
@@ skipping 96 matching lines @@
     BLINK_EXPORT static void enableUnsafeES3APIs(bool);
 
     BLINK_EXPORT static void enableWebVR(bool);
 private:
     WebRuntimeFeatures();
 };
 
 } // namespace blink
 
 #endif