Drive: Mount/Unmount GoogleDrive on Files App when the file system is mounted/unmounted.

chrome/browser/chromeos/gdata/mock_gdata_file_system.h

Index: chrome/browser/chromeos/gdata/mock_gdata_file_system.h
diff --git a/chrome/browser/chromeos/gdata/mock_gdata_file_system.h b/chrome/browser/chromeos/gdata/mock_gdata_file_system.h
index 321bb4d30f538007e0d9e29713c9ad4ab74c93c4..93ae1fdaa2ce7abdcded2f70fd0dd31e30751cdd 100644
--- a/chrome/browser/chromeos/gdata/mock_gdata_file_system.h
+++ b/chrome/browser/chromeos/gdata/mock_gdata_file_system.h
@@ -80,6 +80,8 @@ class MockGDataFileSystem : public GDataFileSystemInterface {
                void(const FilePath& file_path));
   MOCK_METHOD1(GetAvailableSpace,
                void(const GetAvailableSpaceCallback& callback));
+  MOCK_METHOD0(AddDriveMountPoint, void());
+  MOCK_METHOD0(RemoveDriveMountPoint, void());
   // This function is not mockable by gmock because scoped_ptr is not supported.
   virtual void AddUploadedFile(UploadMode upload_mode,
                                const FilePath& file,