Adds USB writing for OS X.

chrome/utility/image_writer/image_writer.h

 // Copyright 2014 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_UTILITY_IMAGE_WRITER_IMAGE_WRITER_H_
 #define CHROME_UTILITY_IMAGE_WRITER_IMAGE_WRITER_H_
 
-#if defined(OS_WIN)
-#include <windows.h>
-#endif
-
-#include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 namespace image_writer {
 
 class ImageWriterHandler;
+#if defined(OS_MACOSX)
+class DiskUnmounterMac;
+#endif
 
 // Manages a write within the utility thread.  This class holds all the state
 // around the writing and communicates with the ImageWriterHandler to dispatch
 // messages.
 class ImageWriter : public base::SupportsWeakPtr<ImageWriter> {
  public:
   explicit ImageWriter(ImageWriterHandler* handler,
                        const base::FilePath& image_path,
                        const base::FilePath& device_path);
   virtual ~ImageWriter();
 
   // Starts a write from |image_path_| to |device_path_|.
   void Write();
   // Starts verifying that |image_path_| and |device_path_| have the same size
   // and contents.
   void Verify();
   // Cancels any pending writes or verifications.
   void Cancel();
 
   // Returns whether an operation is in progress.
   bool IsRunning() const;
   // Checks if a path is a valid target device.
   // This method has OS-specific implementations.
   bool IsValidDevice();
   // Unmounts all volumes on the target device.
   // This method has OS-specific implementations.
-  bool UnmountVolumes();
+  void UnmountVolumes(const base::Closure& continuation);
 
   // Return the current image path.
   const base::FilePath& GetImagePath();
   // Return the current device path.
   const base::FilePath& GetDevicePath();
 
  private:
   // Convenience wrappers.
   void PostTask(const base::Closure& task);
   void PostProgress(int64 progress);
   void Error(const std::string& message);
 
   // Initializes the files.
   bool InitializeFiles();
+  bool OpenDevice();
 
   // Work loops.
   void WriteChunk();
   void VerifyChunk();
 
   base::FilePath image_path_;
   base::FilePath device_path_;
 
   base::File image_file_;
   base::File device_file_;
   int64 bytes_processed_;
   bool running_;
 
 #if defined(OS_WIN)
   std::vector<HANDLE> volume_handles_;
 #endif
 
+#if defined(OS_MACOSX)
+  friend class DiskUnmounterMac;
+  scoped_ptr<DiskUnmounterMac> unmounter_;
+#endif
+
   ImageWriterHandler* handler_;
 };
 
 }  // namespace image_writer
 
 #endif  // CHROME_UTILITY_IMAGE_WRITER_IMAGE_WRITER_H_