Removed uses of IsRunningOnIOS9OrLater in crw_web_ or wk_web_view_

ios/web/web_state/crw_web_view_proxy_impl.mm

 // Copyright 2013 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/web_state/crw_web_view_proxy_impl.h"
 
-#include "base/ios/ios_util.h"
 #include "base/mac/scoped_nsobject.h"
 #import "ios/web/public/web_state/crw_web_view_scroll_view_proxy.h"
 #import "ios/web/public/web_state/ui/crw_content_view.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
@@ skipping 144 matching lines @@
   return _contentView != nil && [_webController contentIsHTML];
 }
 
 - (UIView*)keyboardAccessory {
   if (!_contentView)
     return nil;
   UIView* firstResponder = GetFirstResponderSubview(_contentView);
   return firstResponder.inputAccessoryView;
 }
 
-#if defined(__IPHONE_9_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_9_0
 - (UITextInputAssistantItem*)inputAssistantItem {
-  DCHECK(base::ios::IsRunningOnIOS9OrLater())
-      << "Cannot retrieve inputAssistantItem on iOS versions earlier than 9.";
   if (!_contentView)
     return nil;
   UIView* firstResponder = GetFirstResponderSubview(_contentView);
   return firstResponder.inputAssistantItem;
 }
-#endif
 
 - (BOOL)becomeFirstResponder {
   return [_contentView becomeFirstResponder];
 }
 
 @end