[javascript mode] Use electricInput rather than electricChars

To be more intelligent about what kind of lines to indent.

Author: marijnh

mode/javascript/javascript.js

@@ -656,7 +656,7 @@ CodeMirror.defineMode("javascript", function(config, parserConfig) {
       else return lexical.indented + (closing ? 0 : indentUnit);
     },
 
-    electricChars: ":{}",
+    electricInput: /^\s*(?:case .*?:|default:|\{|\})$/,
     blockCommentStart: jsonMode ? null : "/*",
     blockCommentEnd: jsonMode ? null : "*/",
     lineComment: jsonMode ? null : "//",