Remove the concept of currentItemIndex

ios/shared/chrome/browser/tabs/web_state_list_unittest.mm

 // Copyright 2017 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.
 
 #import "ios/shared/chrome/browser/tabs/web_state_list.h"
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/supports_user_data.h"
 #import "ios/shared/chrome/browser/tabs/fake_web_state_list_delegate.h"
@@ skipping 93 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(WebStateListTestObserver);
 };
 
 // A fake NavigationManager used to test opener-opened relationship in the
 // WebStateList.
 class FakeNavigationManager : public web::TestNavigationManager {
  public:
   FakeNavigationManager() = default;
 
   // web::NavigationManager implementation.
-  int GetCurrentItemIndex() const override { return current_item_index_; }
+  int GetLastCommittedItemIndex() const override {
+    return last_committed_item_index;
+  }
 
-  int GetLastCommittedItemIndex() const override { return current_item_index_; }
+  bool CanGoBack() const override { return last_committed_item_index > 0; }
 
-  bool CanGoBack() const override { return current_item_index_ > 0; }
-
-  bool CanGoForward() const override { return current_item_index_ < INT_MAX; }
+  bool CanGoForward() const override {
+    return last_committed_item_index < INT_MAX;
+  }
 
   void GoBack() override {
     DCHECK(CanGoBack());
-    --current_item_index_;
+    --last_committed_item_index;
   }
 
   void GoForward() override {
     DCHECK(CanGoForward());
-    ++current_item_index_;
+    ++last_committed_item_index;
   }
 
-  void GoToIndex(int index) override { current_item_index_ = index; }
+  void GoToIndex(int index) override { last_committed_item_index = index; }
 
-  int current_item_index_ = 0;
+  int last_committed_item_index = 0;
 
   DISALLOW_COPY_AND_ASSIGN(FakeNavigationManager);
 };
 
 }  // namespace
 
 class WebStateListTest : public PlatformTest {
  public:
   WebStateListTest()
       : web_state_list_(&web_state_list_delegate_,
@@ skipping 392 matching lines @@
             web_state_list_.GetIndexOfLastWebStateOpenedBy(opener, start_index,
                                                            false));
 
   EXPECT_EQ(WebStateList::kInvalidIndex,
             web_state_list_.GetIndexOfNextWebStateOpenedBy(opener, start_index,
                                                            true));
   EXPECT_EQ(WebStateList::kInvalidIndex,
             web_state_list_.GetIndexOfLastWebStateOpenedBy(opener, start_index,
                                                            true));
 }