[ios] Updated CreateMockWKWebViewWithStubbedJSEvalFunction comments.

ios/web/test/wk_web_view_crash_utils.mm

 // Copyright 2014 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/test/wk_web_view_crash_utils.h"
 
 #import <Foundation/Foundation.h>
 #import <WebKit/WebKit.h>
 
 #include "base/ios/ios_util.h"
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
 #include "ios/web/public/test/test_browser_state.h"
 #import "ios/web/public/web_view_creation_util.h"
 #import "third_party/ocmock/OCMock/NSInvocation+OCMAdditions.h"
 #import "third_party/ocmock/OCMock/OCMock.h"
 
 namespace {
 
-// Returns an OCMocked WKWebView whose |evaluateJavaScript:stringResultHandler:|
+// Returns an OCMocked WKWebView whose |evaluateJavaScript:completionHandler:|
 // method has been mocked to execute |block| instead. |block| cannot be nil.
 WKWebView* CreateMockWKWebViewWithStubbedJSEvalFunction(
     void (^block)(NSInvocation*)) {
   DCHECK(block);
   web::TestBrowserState browser_state;
   base::scoped_nsobject<WKWebView> webView(
       web::CreateWKWebView(CGRectZero, &browser_state));
   id mockWebView = [OCMockObject partialMockForObject:webView];
   [[[mockWebView stub] andDo:^void(NSInvocation* invocation) {
       block(invocation);
@@ skipping 34 matching lines @@
   id succeed = ^void(NSInvocation* invocation) {
       void (^completionHandler)(id, NSError*) =
           [invocation getArgumentAtIndexAsObject:3];
       // Always succceeds with nil result.
       completionHandler(nil, nil);
   };
   return CreateMockWKWebViewWithStubbedJSEvalFunction(succeed);
 }
 
 }  // namespace web