Add a Content API around BrowserURLHandler.

content/browser/browser_url_handler.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.
-
-// We handle some special browser-level URLs (like "about:version")
-// before they're handed to a renderer.  This lets us do the URL handling
-// on the browser side (which has access to more information than the
-// renderers do) as well as sidestep the risk of exposing data to
-// random web pages (because from the resource loader's perspective, these
-// URL schemes don't exist).
-
-#ifndef CONTENT_BROWSER_BROWSER_URL_HANDLER_H_
-#define CONTENT_BROWSER_BROWSER_URL_HANDLER_H_
-#pragma once
-
-#include <vector>
-#include <utility>
-
-#include "base/gtest_prod_util.h"
-#include "base/memory/singleton.h"
-#include "content/common/content_export.h"
-
-class GURL;
-
-namespace content {
-class BrowserContext;
-}
-
-// BrowserURLHandler manages the list of all special URLs and manages
-// dispatching the URL handling to registered handlers.
-class CONTENT_EXPORT BrowserURLHandler {
- public:
-  // The type of functions that can process a URL.
-  // If a handler handles |url|, it should :
-  // - optionally modify |url| to the URL that should be sent to the renderer
-  // If the URL is not handled by a handler, it should return false.
-  typedef bool (*URLHandler)(GURL* url,
-                             content::BrowserContext* browser_context);
-
-  // Returns the singleton instance.
-  static BrowserURLHandler* GetInstance();
-
-  // RewriteURLIfNecessary gives all registered URLHandlers a shot at processing
-  // the given URL, and modifies it in place.
-  // If the original URL needs to be adjusted if the modified URL is redirected,
-  // this function sets |reverse_on_redirect| to true.
-  void RewriteURLIfNecessary(GURL* url,
-                             content::BrowserContext* browser_context,
-                             bool* reverse_on_redirect);
-
-  // Reverses the rewriting that was done for |original| using the new |url|.
-  bool ReverseURLRewrite(GURL* url, const GURL& original,
-                         content::BrowserContext* browser_context);
-
-  // Add the specified handler pair to the list of URL handlers.
-  void AddHandlerPair(URLHandler handler, URLHandler reverse_handler);
-
-  // Returns the null handler for use with |AddHandlerPair()|.
-  static URLHandler null_handler();
-
- private:
-  // This object is a singleton:
-  BrowserURLHandler();
-  ~BrowserURLHandler();
-  friend struct DefaultSingletonTraits<BrowserURLHandler>;
-
-  // The list of known URLHandlers, optionally with reverse-rewriters.
-  typedef std::pair<URLHandler, URLHandler> HandlerPair;
-  std::vector<HandlerPair> url_handlers_;
-
-  FRIEND_TEST_ALL_PREFIXES(BrowserURLHandlerTest, BasicRewriteAndReverse);
-  FRIEND_TEST_ALL_PREFIXES(BrowserURLHandlerTest, NullHandlerReverse);
-
-  DISALLOW_COPY_AND_ASSIGN(BrowserURLHandler);
-};
-
-#endif  // CONTENT_BROWSER_BROWSER_URL_HANDLER_H_