Move RTCPeerConnection to correct location to generate the supported check for

tools/dom/templates/html/impl/impl_RTCPeerConnection.darttemplate

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of $LIBRARYNAME;
 
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$if DART2JS
   factory $CLASSNAME(Map rtcIceServers, [Map mediaConstraints]) {
     var constructorName = JS('RtcPeerConnection', 'window[#]',
         '${_browserPropertyPrefix}RTCPeerConnection');
     if (?mediaConstraints) {
       return JS('RtcPeerConnection', 'new #(#,#)', constructorName,
           convertDartToNative_SerializedScriptValue(rtcIceServers),
           convertDartToNative_SerializedScriptValue(mediaConstraints));
     } else {
       return JS('RtcPeerConnection', 'new #(#)', constructorName,
           convertDartToNative_SerializedScriptValue(rtcIceServers));
     }
   }
+$endif
 
   /**
    * Checks if Real Time Communication (RTC) APIs are supported and enabled on 
    * the current platform.
    */
 $if DART2JS
   static bool get supported {
     // Currently in Firefox some of the RTC elements are defined but throw an
     // error unless the user has specifically enabled them in their 
     // about:config. So we have to construct an element to actually test if RTC
     // is supported at at the given time.
     try {
       var c = new RtcPeerConnection({"iceServers": [ {"url":"stun:foo.com"}]});
       return c is RtcPeerConnection; 
     } catch (_) {}
     return false;
   }
 $else
   static bool get supported => true;
 $endif
 $!MEMBERS
 }