Adds API test for imageWriterPrivate.writeFromFile

chrome/browser/extensions/api/image_writer_private/operation.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_OPERATION_H_
 #define CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_OPERATION_H_
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 55 matching lines @@
   void Cancel();
 
   // Aborts the operation, cancelling it and generating an error.
   void Abort();
 
   // Informational getters.
   int GetProgress();
   image_writer_api::Stage GetStage();
 
 #if !defined(OS_CHROMEOS)
-  // Set an ImageWriterClient to use.  Should be called only when testing.
-  void SetUtilityClientForTesting(
+  // Set an ImageWriterClient to use.  Should be called only when testing.  This
+  // does not set up automatic shutdown of the client and it must be shutdown
+  // manually.
+  static void SetUtilityClientForTesting(
       scoped_refptr<ImageWriterUtilityClient> client);
 #endif
 
  protected:
   virtual ~Operation();
 
   // This function should be overriden by subclasses to set up the work of the
   // operation.  It will be called from Start().
   virtual void StartImpl() = 0;
 
@@ skipping 123 matching lines @@
 
   // CleanUp operations that must be run.  All these functions are run on the
   // FILE thread.
   std::vector<base::Closure> cleanup_functions_;
 };
 
 }  // namespace image_writer
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_OPERATION_H_