Coverity: Fix a few pass-by-values.

chrome/common/extensions/extension_file_util.h

 // Copyright (c) 2012 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_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_
 #pragma once
 
 #include <string>
 #include <map>
 
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_message_bundle.h"
 
 class Extension;
 class ExtensionMessageBundle;
 class FilePath;
 class GURL;
 namespace base {
 class DictionaryValue;
 }
 
-// Utilties for manipulating the on-disk storage of extensions.
+// Utilities for manipulating the on-disk storage of extensions.
 namespace extension_file_util {
 
 // The name of the directory inside the profile that we store installed
 // extension in.
 extern const char kInstallDirectoryName[];
 
 // Copies |unpacked_source_dir| into the right location under |extensions_dir|.
-// The destination directiory is returned on success, or empty path is returned
+// The destination directory is returned on success, or empty path is returned
 // on failure.
 FilePath InstallExtension(const FilePath& unpacked_source_dir,
                           const std::string& id,
                           const std::string& version,
                           const FilePath& extensions_dir);
 
 // Removes all versions of the extension with |id| from |extensions_dir|.
 void UninstallExtension(const FilePath& extensions_dir,
                         const std::string& id);
 
 // Loads and validates an extension from the specified directory. Returns NULL
 // on failure, with a description of the error in |error|.
 scoped_refptr<Extension> LoadExtension(const FilePath& extension_root,
                                        Extension::Location location,
                                        int flags,
                                        std::string* error);
 
 // The same as LoadExtension except use the provided |extension_id|.
 scoped_refptr<Extension> LoadExtension(const FilePath& extension_root,
-                                       std::string extension_id,
+                                       const std::string& extension_id,
                                        Extension::Location location,
                                        int flags,
                                        std::string* error);
 
 // Loads an extension manifest from the specified directory. Returns NULL
 // on failure, with a description of the error in |error|.
 base::DictionaryValue* LoadManifest(const FilePath& extension_root,
                                     std::string* error);
 
 // Returns true if the given extension object is valid and consistent.
@@ skipping 45 matching lines @@
 FilePath GetUserDataTempDir();
 
 // Helper function to delete files. This is used to avoid ugly casts which
 // would be necessary with PostMessage since file_util::Delete is overloaded.
 // TODO(skerner): Make a version of Delete that is not overloaded in file_util.
 void DeleteFile(const FilePath& path, bool recursive);
 
 }  // namespace extension_file_util
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_