Remove CloseFile from FileSystem.

chrome/browser/chromeos/drive/dummy_file_system.h

Index: chrome/browser/chromeos/drive/dummy_file_system.h
diff --git a/chrome/browser/chromeos/drive/dummy_file_system.h b/chrome/browser/chromeos/drive/dummy_file_system.h
index e9b95b55d9b9c600687e75b635f49e5334a5d698..92e546fd9c4dc800a9aaa2de45ffc881f062589b 100644
--- a/chrome/browser/chromeos/drive/dummy_file_system.h
+++ b/chrome/browser/chromeos/drive/dummy_file_system.h
@@ -28,8 +28,6 @@ class DummyFileSystem : public FileSystemInterface {
   virtual void OpenFile(const base::FilePath& file_path,
                         OpenMode open_mode,
                         const OpenFileCallback& callback) OVERRIDE {}
-  virtual void CloseFile(const base::FilePath& file_path,
-                         const FileOperationCallback& callback) OVERRIDE {}
   virtual void Copy(const base::FilePath& src_file_path,
                     const base::FilePath& dest_file_path,
                     const FileOperationCallback& callback) OVERRIDE {}
@@ -85,7 +83,7 @@ class DummyFileSystem : public FileSystemInterface {
       const GetFilesystemMetadataCallback& callback) OVERRIDE {}
   virtual void MarkCacheFileAsMounted(
       const base::FilePath& drive_file_path,
-      const OpenFileCallback& callback) OVERRIDE {}
+      const MarkMountedCallback& callback) OVERRIDE {}
   virtual void MarkCacheFileAsUnmounted(
       const base::FilePath& cache_file_path,
       const FileOperationCallback& callback) OVERRIDE {}