Remove Earl Grey matcher APIs taking NSString.

ios/web/shell/test/earl_grey/shell_matchers.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/shell/test/earl_grey/shell_matchers.h"
 
 #import "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/test/ios/wait_util.h"
 #include "ios/testing/earl_grey/wait_util.h"
 #import "ios/web/public/web_state/web_state.h"
 #import "ios/web/public/test/earl_grey/web_view_matchers.h"
 #import "ios/web/shell/test/app/web_shell_test_util.h"
 #import "ios/web/shell/view_controller.h"
 
 namespace web {
 
-id<GREYMatcher> webViewContainingText(NSString* text) {
-  return [GREYMatchers
-      matcherForWebViewContainingText:base::SysNSStringToUTF8(text)];
-}
-
-id<GREYMatcher> addressFieldText(NSString* text) {
-  return [GREYMatchers
-      matcherForAddressFieldEqualToText:base::SysNSStringToUTF8(text)];
-}
-
 id<GREYMatcher> webViewContainingText(const std::string& text) {
   return [GREYMatchers matcherForWebViewContainingText:text];
 }
 
 id<GREYMatcher> addressFieldText(const std::string& text) {
   return [GREYMatchers matcherForAddressFieldEqualToText:text];
 }
 
 id<GREYMatcher> backButton() {
   return [GREYMatchers matcherForWebShellBackButton];
@@ skipping 54 matching lines @@
 
 + (id<GREYMatcher>)matcherForWebShellForwardButton {
   return grey_accessibilityLabel(kWebShellForwardButtonAccessibilityLabel);
 }
 
 + (id<GREYMatcher>)matcherForWebShellAddressField {
   return grey_accessibilityLabel(kWebShellAddressFieldAccessibilityLabel);
 }
 
 @end