[ios] Use range.length instead of range.location for substring matching.

ios/web/web_state/ui/crw_web_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/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 1594 matching lines @@
 }
 
 // Set the specified recognizer to take priority over any recognizers in the
 // view that have a description containing the specified text fragment.
 + (void)requireGestureRecognizerToFail:(UIGestureRecognizer*)recognizer
                                 inView:(UIView*)view
                  containingDescription:(NSString*)fragment {
   for (UIGestureRecognizer* iRecognizer in [view gestureRecognizers]) {
     if (iRecognizer != recognizer) {
       NSString* description = [iRecognizer description];
-      if ([description rangeOfString:fragment].location != NSNotFound) {
+      if ([description rangeOfString:fragment].length) {
         [iRecognizer requireGestureRecognizerToFail:recognizer];
         // requireGestureRecognizerToFail: doesn't retain the recognizer, so it
         // is possible for |iRecognizer| to outlive |recognizer| and end up with
         // a dangling pointer. Add a retaining associative reference to ensure
         // that the lifetimes work out.
         // Note that normally using the value as the key wouldn't make any
         // sense, but here it's fine since nothing needs to look up the value.
         objc_setAssociatedObject(view, recognizer, recognizer,
                                  OBJC_ASSOCIATION_RETAIN_NONATOMIC);
       }
@@ skipping 4039 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end