DevTools: [LiveSASS] do not commit updated SASS sources to file system.

third_party/WebKit/Source/devtools/front_end/bindings/SASSSourceMapping.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 74 matching lines @@
             for (var sourceURL of newSources.keys()) {
                 var uiSourceCode = this._networkMapping.uiSourceCodeForStyleURL(sourceURL, header);
                 if (!uiSourceCode) {
                     console.error("Failed to update source for " + sourceURL);
                     continue;
                 }
                 if (handledUISourceCodes.has(uiSourceCode))
                     continue;
                 handledUISourceCodes.add(uiSourceCode);
                 var sassText = /** @type {string} */(newSources.get(sourceURL));
-                uiSourceCode.addRevision(sassText);
+                uiSourceCode.setWorkingCopy(sassText);
             }
         }
     },
 
     /**
      * @param {!WebInspector.CSSStyleSheetHeader} header
      */
     addHeader: function(header)
     {
         if (!header.sourceMapURL)
@@ skipping 63 matching lines @@
     },
 
     /**
      * @return {!WebInspector.Target}
      */
     target: function()
     {
         return this._cssModel.target();
     }
 }