Use stub impl when libcros fails to load

chrome/browser/chromeos/cros/burn_library.h

 // Copyright (c) 2011 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_CHROMEOS_CROS_BURN_LIBRARY_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_BURN_LIBRARY_H_
 
 #include <string>
 #include <vector>
@@ skipping 49 matching lines @@
 class BurnLibrary {
  public:
   class Observer {
    public:
     virtual void BurnProgressUpdated(BurnLibrary* object, BurnEvent evt,
                                  const ImageBurnStatus& status) = 0;
   };
 
   virtual ~BurnLibrary() {}
 
+  virtual void Init() = 0;
+
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
   // Example values:
   // DoBurn(image.bin.zip, image.bin, /dev/sdb, /sys/devices/pci..../block.sdb).
   virtual void DoBurn(const FilePath& source_path,
                       const std::string& image_name,
                       const FilePath& target_file_path,
                       const FilePath& target_device_path) = 0;
   virtual void CancelBurnImage() = 0;
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via CrosLibrary::Get().
   static BurnLibrary* GetImpl(bool stub);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_BURN_LIBRARY_H_