Revert "Remove VisitedLink dependency on rest of chrome"

chrome/browser/visitedlink/visitedlink_delegate.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_VISITEDLINK_VISITEDLINK_DELEGATE_H_
-#define CHROME_BROWSER_VISITEDLINK_VISITEDLINK_DELEGATE_H_
-
-class GURL;
-
-namespace content {
-class BrowserContext;
-}  // namespace content
-
-// Delegate class that clients of VisitedLinkMaster must implement.
-class VisitedLinkDelegate {
- public:
-  // Returns true when the two BrowserContexts are equivalent.
-  virtual bool AreEquivalentContexts(content::BrowserContext* context1,
-                                     content::BrowserContext* context2) = 0;
-
-  // See RebuildTable.
-  class URLEnumerator {
-   public:
-    // Call this with each URL to rebuild the table.
-    virtual void OnURL(const GURL& url) = 0;
-
-    // This must be called by Delegate after RebuildTable is called. |success|
-    // indicates all URLs have been returned successfully. The URLEnumerator
-    // object cannot be used by the delegate after this call.
-    virtual void OnComplete(bool success) = 0;
-
-   protected:
-    virtual ~URLEnumerator() {}
-  };
-
-  // Delegate class is responsible for persisting the list of visited URLs
-  // across browser runs. This is called by VisitedLinkMaster to repopulate
-  // its internal table. Note that methods on enumerator can be called on any
-  // thread but the delegate is responsible for synchronizating the calls.
-  virtual void RebuildTable(URLEnumerator* enumerator) = 0;
-
- protected:
-  virtual ~VisitedLinkDelegate() {}
-};
-
-#endif  // CHROME_BROWSER_VISITEDLINK_VISITEDLINK_DELEGATE_H_