[ios] Fixed Resetting the page for unit tests.

ios/web/public/test/web_test_with_web_state.mm

 // Copyright 2016 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/public/test/web_test_with_web_state.h"
 
 #import <WebKit/WebKit.h>
 
 #include "base/base64.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 137 matching lines @@
   base::test::ios::WaitUntilCondition(condition, messageLoop,
                                       base::TimeDelta::FromSeconds(10));
 }
 
 id WebTestWithWebState::ExecuteJavaScript(NSString* script) {
   __block base::scoped_nsprotocol<id> executionResult;
   __block bool executionCompleted = false;
   [GetWebController(web_state())
       executeJavaScript:script
       completionHandler:^(id result, NSError* error) {
-        if (error && error.code != WKErrorJavaScriptResultTypeIsUnsupported) {
-          NOTREACHED() << " error: " << error.code
-                       << " for script: " << base::SysNSStringToUTF8(script);
-        }
         executionResult.reset([result copy]);
         executionCompleted = true;
       }];
   base::test::ios::WaitUntilCondition(^{
     return executionCompleted;
   });
   return [[executionResult retain] autorelease];
 }
 
 std::string WebTestWithWebState::BaseUrl() const {
   web::URLVerificationTrustLevel unused_level;
   return web_state()->GetCurrentURL(&unused_level).spec();
 }
 
 web::WebState* WebTestWithWebState::web_state() {
   return web_state_.get();
 }
 
 const web::WebState* WebTestWithWebState::web_state() const {
   return web_state_.get();
 }
 
 bool WebTestWithWebState::ResetPageIfNavigationStalled(NSString* load_check) {
   id inner_html = ExecuteJavaScript(
       @"(document && document.body && document.body.innerHTML) || 'undefined'");
-  if ([inner_html rangeOfString:load_check].location == NSNotFound) {
+  if (![inner_html rangeOfString:load_check].length) {
     web_state_->SetWebUsageEnabled(false);
     web_state_->SetWebUsageEnabled(true);
     [GetWebController(web_state()) triggerPendingLoad];
     return true;
   }
   return false;
 }
 
 NSString* WebTestWithWebState::CreateLoadCheck() {
   return [NSString stringWithFormat:@"<p style=\"display: none;\">%d</p>",
                                     s_html_load_count++];
 }
 
 }  // namespace web