Renames SessionChanges and SessionCellData to have a TabSwitcher prefix.

ios/chrome/browser/ui/tab_switcher/session_changes.h

-// Copyright 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 IOS_CHROME_BROWSER_UI_TAB_SWITCHER_SESSION_CHANGES_H_
-#define IOS_CHROME_BROWSER_UI_TAB_SWITCHER_SESSION_CHANGES_H_
-
-#include <vector>
-
-// This structure represents the changes a session undergoes.
-// It is used to update the UICollectionView showing a set of tabs.
-class SessionChanges {
- public:
-  SessionChanges(std::vector<size_t> const& tabHashesInInitialState,
-                 std::vector<size_t> const& tabHashesInFinalState);
-  ~SessionChanges();
-  SessionChanges(const SessionChanges& sessionChanges) = delete;
-  SessionChanges& operator=(const SessionChanges& sessionChanges) = delete;
-
-  std::vector<size_t> const& deletions() const;
-  std::vector<size_t> const& insertions() const;
-  std::vector<size_t> const& updates() const;
-
-  bool hasChanges() const;
-
- private:
-  // Those vectors contain indexes of tabs.
-  // The indexes are relative to a tab model snapshot, or a distant session.
-  // To be in accordance with the UICollectionView's |performBatchUpdates|
-  // method:
-  // -the indexes in |updates| are relative to the previous state of the
-  // session.
-  // -the indexes in |deletions| are relative to the previous state of the
-  // session.
-  // -the indexes in |insertions| are relative to the final state of the
-  // session.
-  std::vector<size_t> deletions_;
-  std::vector<size_t> insertions_;
-  std::vector<size_t> updates_;
-};
-
-#endif  // IOS_CHROME_BROWSER_UI_TAB_SWITCHER_SESSION_CHANGES_H_