DevTools: add extension API to contribute trace events to timeline

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 445 matching lines @@
       if (fileSize === -1)
         return;
       if (chunk) {
         chunk.startOffset = this._fileSize;
         chunk.endOffset = fileSize;
         chunk.string = null;
       }
       this._fileSize = fileSize;
     }
 
+    if (!this._file)
+      this._file = new Bindings.DeferredTempFile(this._dirName, String(Date.now()));
     this._file.write(this._strings, didWrite.bind(this, chunk));
     this._strings = [];
     this._stringsLength = 0;
     return chunk;
   }
 
   /**
    * @override
    */
   finishWriting() {
     this._flush(false);
     this._file.finishWriting(function() {});
   }
 
   /**
    * @override
    */
   reset() {
     if (this._file)
       this._file.remove();
-    this._file = new Bindings.DeferredTempFile(this._dirName, String(Date.now()));
+    this._file = null;
     /**
      * @type {!Array.<string>}
      */
     this._strings = [];
     this._stringsLength = 0;
     this._fileSize = 0;
   }
 
   /**
    * @param {!Common.OutputStream} outputStream
    * @param {!Bindings.OutputStreamDelegate} delegate
    */
   writeToStream(outputStream, delegate) {
-    this._file.copyToOutputStream(outputStream, delegate);
+    if (this._file)
+      this._file.copyToOutputStream(outputStream, delegate);
   }
 };
 
 /**
  * @typedef {{
  *      string: ?string,
  *      startOffset: number,
  *      endOffset: number
  * }}
  */
 Bindings.TempFileBackingStorage.Chunk;