DevTools: show filesystem file by default

third_party/WebKit/Source/devtools/front_end/bindings/ResourceScriptMapping.js

 /*
  * Copyright (C) 2012 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 278 matching lines @@
    * @return {boolean}
    */
   _isDiverged() {
     if (this._uiSourceCode.isDirty())
       return true;
     if (!this._script)
       return false;
     if (typeof this._scriptSource === 'undefined')
       return false;
     var workingCopy = this._uiSourceCode.workingCopy();
+    if (!workingCopy)
+      return false;
 
     // Match ignoring sourceURL.
     if (!workingCopy.startsWith(this._scriptSource.trimRight()))
       return true;
     var suffix = this._uiSourceCode.workingCopy().substr(this._scriptSource.length);
     return !!suffix.length && !suffix.match(SDK.Script.sourceURLRegex);
   }
 
   /**
    * @param {!Common.Event} event
@@ skipping 130 matching lines @@
   hasSourceMapURL() {
     return this._script && !!this._script.sourceMapURL;
   }
 };
 
 /** @enum {symbol} */
 Bindings.ResourceScriptFile.Events = {
   DidMergeToVM: Symbol('DidMergeToVM'),
   DidDivergeFromVM: Symbol('DidDivergeFromVM'),
 };