chrome: Put browser_navigator.h into chrome namespace.

chrome/browser/ui/singleton_tabs.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_BROWSER_UI_SINGLETON_TABS_H_
 #define CHROME_BROWSER_UI_SINGLETON_TABS_H_
 #pragma once
 
 class Browser;
 class GURL;
 
-namespace browser {
-struct NavigateParams;
-}
-
 // Methods for opening "singleton tabs". Tabs are guaranteed unique by varying
 // metrics within a particular Browser window.
 
 namespace chrome {
 
+struct NavigateParams;
+
 // Core singleton tab API:
 
 // Show a given a URL. If a tab with the same URL (ignoring the ref) is
 // already visible in this browser, it becomes selected. Otherwise a new tab
 // is created.
 void ShowSingletonTab(Browser* browser, const GURL& url);
 
 // Same as ShowSingletonTab, but does not ignore ref.
 void ShowSingletonTabRespectRef(Browser* browser, const GURL& url);
 
 // As ShowSingletonTab, but if the current tab is the new tab page or
 // about:blank, then overwrite it with the passed contents.
 void ShowSingletonTabOverwritingNTP(Browser* browser,
-                                    const browser::NavigateParams& params);
+                                    const NavigateParams& params);
 
 // Creates a NavigateParams struct for a singleton tab navigation.
-browser::NavigateParams GetSingletonTabNavigateParams(Browser* browser,
-                                                      const GURL& url);
+NavigateParams GetSingletonTabNavigateParams(Browser* browser, const GURL& url);
 
 // If the given navigational URL is a Singleton, return the tab index for it.
 // Otherwise, returns -1.
-int GetIndexOfSingletonTab(browser::NavigateParams* params);
+int GetIndexOfSingletonTab(NavigateParams* params);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_SINGLETON_TABS_H_