[DevTools] Fix compile errors before closure compiler roll

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

 /*
  * Copyright (C) 2013 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 215 matching lines @@
     }
 }
 
 /**
  * @constructor
  * @param {string} dirPath
  * @param {string} name
  */
 WebInspector.DeferredTempFile = function(dirPath, name)
 {
-    /** @type {!Array.<!{strings: !Array.<string>, callback: function(number)}>} */
+    /** @type {!Array.<!{strings: !Array.<string>, callback: ?function(number)}>} */
     this._chunks = [];
     this._tempFile = null;
     this._isWriting = false;
     this._finishCallback = null;
     this._finishedWriting = false;
     this._callsPendingOpen = [];
     this._pendingReads = [];
     WebInspector.TempFile.create(dirPath, name)
         .then(this._didCreateTempFile.bind(this), this._failedToCreateTempFile.bind(this));
 }
 
 WebInspector.DeferredTempFile.prototype = {
     /**
      * @param {!Array.<string>} strings
      * @param {function(number)=} callback
      */
     write: function(strings, callback)
     {
         if (this._finishCallback)
             throw new Error("No writes are allowed after close.");
-        this._chunks.push({strings: strings, callback: callback});
+        this._chunks.push({strings: strings, callback: callback || null});
         if (this._tempFile && !this._isWriting)
             this._writeNextChunk();
     },
 
     /**
      * @param {function(?WebInspector.TempFile)} callback
      */
     finishWriting: function(callback)
     {
         this._finishCallback = callback;
@@ skipping 316 matching lines @@
 
     /**
      * @param {!WebInspector.OutputStream} outputStream
      * @param {!WebInspector.OutputStreamDelegate} delegate
      */
     writeToStream: function(outputStream, delegate)
     {
         this._file.copyToOutputStream(outputStream, delegate);
     }
 }