[TabManager] Move TabManager into chrome/browser/resource_coordinator.

chrome/browser/memory/tab_manager_observer.h

-// Copyright (c) 2016 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_MEMORY_TAB_MANAGER_OBSERVER_H_
-#define CHROME_BROWSER_MEMORY_TAB_MANAGER_OBSERVER_H_
-
-namespace content {
-class WebContents;
-}
-
-namespace memory {
-
-// Interface for objects that wish to be notified of changes in TabManager.
-class TabManagerObserver {
- public:
-  // Invoked when the Discarded state changes.
-  // Sends the WebContents of the tab that had the discarded property changed
-  // and the current state to let observers know if it is discarderd or not.
-  virtual void OnDiscardedStateChange(content::WebContents* contents,
-                                      bool is_discarded);
-
-  // Invoked when the auto-discardable state changes.
-  virtual void OnAutoDiscardableStateChange(content::WebContents* contents,
-                                            bool is_auto_discardable);
-
- protected:
-  virtual ~TabManagerObserver();
-};
-
-}  // namespace memory
-
-#endif  // CHROME_BROWSER_MEMORY_TAB_MANAGER_OBSERVER_H_