Coverity: Pass parameters by reference.

chrome/browser/extensions/extension_menu_manager.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_EXTENSIONS_EXTENSION_MENU_MANAGER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_MENU_MANAGER_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 18 matching lines @@
 
 // Represents a menu item added by an extension.
 class ExtensionMenuItem {
  public:
   // A list of ExtensionMenuItem's.
   typedef std::vector<ExtensionMenuItem*> List;
 
   // An Id uniquely identifies a context menu item registered by an extension.
   struct Id {
     Id();
-    Id(Profile* profile, std::string extension_id, int uid);
+    Id(Profile* profile, const std::string& extension_id, int uid);
     ~Id();
 
     bool operator==(const Id& other) const;
     bool operator!=(const Id& other) const;
     bool operator<(const Id& other) const;
 
     Profile* profile;
     std::string extension_id;
     int uid;
   };
@@ skipping 42 matching lines @@
     }
 
     void Add(Context context) {
       value_ |= context;
     }
 
    private:
     uint32 value_;  // A bitmask of Context values.
   };
 
-  ExtensionMenuItem(const Id& id, std::string title, bool checked, Type type,
+  ExtensionMenuItem(const Id& id,
+                    const std::string& title,
+                    bool checked,
+                    Type type,
                     const ContextList& contexts);
   virtual ~ExtensionMenuItem();
 
   // Simple accessor methods.
   const std::string& extension_id() const { return id_.extension_id; }
   const std::string& title() const { return title_; }
   const List& children() { return children_; }
   const Id& id() const { return id_; }
   Id* parent_id() const { return parent_id_.get(); }
   int child_count() const { return children_.size(); }
@@ skipping 162 matching lines @@
   std::map<ExtensionMenuItem::Id, ExtensionMenuItem*> items_by_id_;
 
   NotificationRegistrar registrar_;
 
   ExtensionIconManager icon_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionMenuManager);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_MENU_MANAGER_H_