Create ChromeEarlGrey waitForWebViewContainingText.

ios/chrome/test/earl_grey/chrome_earl_grey.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/chrome/test/earl_grey/chrome_earl_grey.h"
 
 #import <Foundation/Foundation.h>
 #import <WebKit/WebKit.h>
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #import "base/test/ios/wait_util.h"
 #include "components/strings/grit/components_strings.h"
 #import "ios/chrome/browser/ui/commands/generic_chrome_command.h"
 #include "ios/chrome/browser/ui/commands/ios_command_ids.h"
 #import "ios/chrome/browser/ui/static_content/static_html_view_controller.h"
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/chrome/test/app/history_test_util.h"
 #include "ios/chrome/test/app/navigation_test_util.h"
 #import "ios/chrome/test/app/static_html_view_test_util.h"
 #import "ios/testing/wait_util.h"
 #import "ios/web/public/test/earl_grey/js_test_util.h"
+#import "ios/web/public/test/web_view_content_test_util.h"
 #import "ios/web/public/test/web_view_interaction_test_util.h"
 #import "ios/web/public/web_state/js/crw_js_injection_receiver.h"
 #import "ios/web/public/web_state/web_state.h"
 #include "ui/base/l10n/l10n_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace chrome_test_util {
@@ skipping 143 matching lines @@
       conditionWithName:@"Wait for absence of static HTML text."
                   block:^BOOL {
                     return !chrome_test_util::StaticHtmlViewContainingText(
                         chrome_test_util::GetCurrentWebState(),
                         base::SysNSStringToUTF8(text));
                   }];
   GREYAssert([condition waitWithTimeout:testing::kWaitForUIElementTimeout],
              @"Failed, there was a static html view containing %@", text);
 }
 
++ (void)waitForWebViewContainingText:(std::string)text {
+  GREYCondition* condition = [GREYCondition
+      conditionWithName:@"Wait for web view containing text"
+                  block:^BOOL {
+                    return web::test::IsWebViewContainingText(
+                        chrome_test_util::GetCurrentWebState(), text);
+                  }];
+  GREYAssert([condition waitWithTimeout:testing::kWaitForUIElementTimeout],
+             @"Failed waiting for web view containing %s", text.c_str());
+}
 @end