DevTools: Allow setting -0 value to object property

Source/devtools/front_end/RemoteObject.js

 /*
  * Copyright (C) 2009 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 267 matching lines @@
      * @param {function(string=)} callback
      */
     doSetObjectPropertyValue: function(result, name, callback)
     {
         // This assignment may be for a regular (data) property, and for an acccessor property (with getter/setter).
         // Note the sensitive matter about accessor property: the property may be physically defined in some proto object,
         // but logically it is bound to the object in question. JavaScript passes this object to getters/setters, not the object
         // where property was defined; so do we.
         var setPropertyValueFunction = "function(a, b) { this[a] = b; }";
 
-        // Special case for NaN, Infinity and -Infinity
-        if (result.type === "number" && typeof result.value !== "number")
+        // Special case for NaN, Infinity, -Infinity, -0.
+        if (result.type === "number" && String(result.value) !== result.description)
             setPropertyValueFunction = "function(a) { this[a] = " + result.description + "; }";
 
         delete result.description; // Optimize on traffic.
         RuntimeAgent.callFunctionOn(this._objectId, setPropertyValueFunction, [{ value:name }, result], true, undefined, undefined, propertySetCallback.bind(this));
 
         /**
          * @param {?Protocol.Error} error
          * @param {RuntimeAgent.RemoteObject} result
          * @param {boolean=} wasThrown
          */
@@ skipping 508 matching lines @@
     },
 
     /**
      * @return {number}
      */
     arrayLength: function()
     {
         return this._value instanceof Array ? this._value.length : 0;
     }
 }