[ios] Removed -[CRWSessionController goDelta:].

ios/web/navigation/crw_session_controller.mm

 // Copyright 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.
 
 #import "ios/web/navigation/crw_session_controller.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 581 matching lines @@
 
   _previousNavigationIndex = -1;
   _currentNavigationIndex += lastIndexToCopy + 1;
   if (_pendingEntryIndex != -1)
     _pendingEntryIndex += lastIndexToCopy + 1;
 
   DCHECK_LT(static_cast<NSUInteger>(_currentNavigationIndex), _entries.count);
   DCHECK(_pendingEntryIndex == -1 || _pendingEntry);
 }
 
-- (BOOL)canGoDelta:(int)delta {
-  NSInteger index = [self indexOfEntryForDelta:delta];
-  return 0 <= index && static_cast<NSUInteger>(index) < _entries.count;
-}
-
 - (void)goToEntryAtIndex:(NSInteger)index {
   if (index < 0 || static_cast<NSUInteger>(index) >= _entries.count)
     return;
 
   if (index < _currentNavigationIndex) {
     // Going back.
     [self discardNonCommittedEntries];
   } else if (_currentNavigationIndex < index) {
     // Going forward.
     [self discardTransientEntry];
@@ skipping 210 matching lines @@
   return [[CRWSessionEntry alloc] initWithNavigationItem:std::move(item)];
 }
 
 - (BOOL)isRedirectTransitionForEntryAtIndex:(NSInteger)index {
   ui::PageTransition transition =
       [_entries[index] navigationItem]->GetTransitionType();
   return (transition & ui::PAGE_TRANSITION_IS_REDIRECT_MASK) ? YES : NO;
 }
 
 @end