[ios] EarlGrey test for scroll position restoration.

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(const std::string& text) {
   return [GREYMatchers matcherForWebViewContainingText:text];
 }
 
+id<GREYMatcher> webViewScrollView() {
+  return [GREYMatchers matcherForWebViewScrollView];
+}
+
 id<GREYMatcher> addressFieldText(const std::string& text) {
   return [GREYMatchers matcherForAddressFieldEqualToText:text];
 }
 
 id<GREYMatcher> backButton() {
   return [GREYMatchers matcherForWebShellBackButton];
 }
 
 id<GREYMatcher> forwardButton() {
   return [GREYMatchers matcherForWebShellForwardButton];
 }
 
 id<GREYMatcher> addressField() {
   return [GREYMatchers matcherForWebShellAddressField];
 }
 
 }  // namespace web
 
 @implementation GREYMatchers (WebShellAdditions)
 
 + (id<GREYMatcher>)matcherForWebViewContainingText:(const std::string&)text {
   web::WebState* webState = web::shell_test_util::GetCurrentWebState();
   return web::webViewContainingText(text, webState);
 }
 
++ (id<GREYMatcher>)matcherForWebViewScrollView {
+  return web::webViewScrollView(web::shell_test_util::GetCurrentWebState());
+}
+
 + (id<GREYMatcher>)matcherForAddressFieldEqualToText:(const std::string&)text {
   MatchesBlock matches = ^BOOL(UIView* view) {
     if (![view isKindOfClass:[UITextField class]]) {
       return NO;
     }
     if (![[view accessibilityLabel]
             isEqualToString:kWebShellAddressFieldAccessibilityLabel]) {
       return NO;
     }
     UITextField* textField = base::mac::ObjCCastStrict<UITextField>(view);
@@ skipping 19 matching lines @@
 
 + (id<GREYMatcher>)matcherForWebShellForwardButton {
   return grey_accessibilityLabel(kWebShellForwardButtonAccessibilityLabel);
 }
 
 + (id<GREYMatcher>)matcherForWebShellAddressField {
   return grey_accessibilityLabel(kWebShellAddressFieldAccessibilityLabel);
 }
 
 @end