Renaming poorly named classes and adding missing unit tests.

chrome/browser/prerender/prerender_tracker.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_PRERENDER_PRERENDER_TRACKER_H_
-#define CHROME_BROWSER_PRERENDER_PRERENDER_TRACKER_H_
-#pragma once
-
-#include <map>
-#include <set>
-#include <vector>
-
-#include "base/gtest_prod_util.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/non_thread_safe.h"
-#include "chrome/browser/prerender/prerender_final_status.h"
-#include "googleurl/src/gurl.h"
-
-namespace prerender {
-
-class PrerenderManager;
-struct RenderViewInfo;
-
-// PrerenderTracker is responsible for keeping track of all prerendering
-// RenderViews and their statuses.  Its list is guaranteed to be up to date
-// and can be modified on any thread.
-class PrerenderTracker {
- public:
-  PrerenderTracker();
-  ~PrerenderTracker();
-
-  // Attempts to set the status of the specified RenderViewHost to
-  // FINAL_STATUS_USED.  Returns true on success.  Returns false if it has
-  // already been cancelled for any reason or is no longer prerendering.
-  // Can only be called only on the IO thread.  This method will not call
-  // PrerenderContents::set_final_status() on the corresponding
-  // PrerenderContents.
-  //
-  // If it returns true, all subsequent calls to TryCancel and TryUse for the
-  // RenderView will return false.
-  bool TryUse(int child_id, int route_id);
-
-  // Attempts to cancel prerendering by the specified RenderView, setting the
-  // FinalStatus to |final_status|.  Returns true if the specified prerender has
-  // been cancelled, either as a result of this call or for any other reason.
-  // If the call results in cancelling a PrerenderContents, a task to destroy
-  // it is also posted to the UI thread.
-  //
-  // When true is returned, it is guaranteed that the RenderView will never
-  // be displayed.  When false is returned, the RenderView has either been
-  // swapped into a tab or has already been destroyed.
-  bool TryCancel(int child_id, int route_id, FinalStatus final_status);
-
-  // Same as above, but can only called on the IO Thread.  Does not acquire a
-  // lock when the RenderView is not being prerendered.
-  bool TryCancelOnIOThread(int child_id, int route_id,
-                           FinalStatus final_status);
-
-  // Gets the FinalStatus of the specified prerendered RenderView.  Returns
-  // |true| and sets |final_status| to the status of the RenderView if it
-  // is found, returns false otherwise.
-  bool GetFinalStatus(int child_id, int route_id,
-                      FinalStatus* final_status) const;
-
-  // Returns whether or not a RenderView is prerendering.  Can only be called on
-  // the IO thread.  Does not acquire a lock, so may claim a RenderView that has
-  // been displayed or destroyed is still prerendering.
-  bool IsPrerenderingOnIOThread(int child_id, int route_id) const;
-
- private:
-  friend class PrerenderContents;
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerNull);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerUsed);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelled);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledOnIO);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledFast);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerMultiple);
-
-  typedef std::pair<int, int> ChildRouteIdPair;
-  // Map of child/route id pairs to final statuses.
-  typedef std::map<ChildRouteIdPair, RenderViewInfo> FinalStatusMap;
-  // Set of child/route id pairs that may be prerendering.
-  typedef std::set<ChildRouteIdPair> PossiblyPrerenderingChildRouteIdPairs;
-
-  // Must be called when a RenderView starts prerendering, before the first
-  // navigation starts to avoid any races.
-  void OnPrerenderingStarted(int child_id, int route_id,
-                             PrerenderManager* prerender_manager);
-
-  // Must be called when a RenderView stops prerendering, either because the
-  // RenderView was used or prerendering was cancelled and it is being
-  // destroyed.
-  void OnPrerenderingFinished(int child_id, int route_id);
-
-  // Attempts to set the FinalStatus of the specified RenderView to
-  // |desired_final_status|.  If non-NULL, |actual_final_status| is set to the
-  // FinalStatus of the RenderView.
-  //
-  // If the FinalStatus of the RenderView is successfully set, returns true and
-  // sets |actual_final_status| to |desired_final_status|.
-  //
-  // If the FinalStatus of the RenderView was already set, returns false and
-  // sets |actual_final_status| to the actual FinalStatus of the RenderView.
-  //
-  // If the RenderView is not a prerendering RenderView, returns false and sets
-  // |actual_final_status| to FINAL_STATUS_MAX.
-  bool SetFinalStatus(int child_id, int route_id,
-                      FinalStatus desired_final_status,
-                      FinalStatus* actual_final_status);
-
-  // Add/remove the specified pair to |possibly_prerendering_io_thread_set_| on
-  // the IO Thread.
-  void AddPrerenderOnIOThread(const ChildRouteIdPair& child_route_id_pair);
-  void RemovePrerenderOnIOThread(const ChildRouteIdPair& child_route_id_pair);
-
-  // Tasks posted to the IO Thread to call the above functions.
-  static void AddPrerenderOnIOThreadTask(
-      const ChildRouteIdPair& child_route_id_pair);
-  static void RemovePrerenderOnIOThreadTask(
-      const ChildRouteIdPair& child_route_id_pair);
-
-  static PrerenderTracker* GetDefault();
-
-  // |final_status_map_lock_| protects access to |final_status_map_|.
-  mutable base::Lock final_status_map_lock_;
-  // Map containing child/route id pairs and their final statuses.  Must only be
-  // accessed while the lock is held.  Values are always accurate and up to
-  // date.
-  FinalStatusMap final_status_map_;
-
-  // Superset of child/route id pairs that are prerendering.  Can only access on
-  // the IO thread.  May contain entries that have since been displayed.  Only
-  // used to prevent locking when not needed.
-  PossiblyPrerenderingChildRouteIdPairs possibly_prerendering_io_thread_set_;
-
-  DISALLOW_COPY_AND_ASSIGN(PrerenderTracker);
-};
-
-}  // namespace prerender
-
-#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_TRACKER_H_