Use stub impl when libcros fails to load

chrome/browser/chromeos/cros/mock_mount_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_MOCK_MOUNT_LIBRARY_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_MOCK_MOUNT_LIBRARY_H_
 #pragma once
 
 #include <string>
 
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "chrome/browser/chromeos/cros/mount_library.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/cros/chromeos_mount.h"
 
 namespace chromeos {
 
 class MockMountLibrary : public MountLibrary {
  public:
   MockMountLibrary();
   virtual ~MockMountLibrary();
 
+  MOCK_METHOD0(Init, void(void));
   MOCK_METHOD1(AddObserver, void(MountLibrary::Observer*));
   MOCK_METHOD1(RemoveObserver, void(MountLibrary::Observer*));
   MOCK_CONST_METHOD0(disks, const MountLibrary::DiskMap&(void));
   MOCK_CONST_METHOD0(mount_points, const MountLibrary::MountPointMap&(void));
 
   MOCK_METHOD0(RequestMountInfoRefresh, void(void));
   MOCK_METHOD3(MountPath, void(const char*, MountType,
                                const MountPathOptions&));
   MOCK_METHOD1(UnmountPath, void(const char*));
   MOCK_METHOD1(FormatUnmountedDevice, void(const char*));
@@ skipping 21 matching lines @@
 
   // The list of disks found.
   MountLibrary::DiskMap disks_;
 
   DISALLOW_COPY_AND_ASSIGN(MockMountLibrary);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_MOCK_MOUNT_LIBRARY_H_