Create ChromeEarlGrey waitForWebViewContainingText.

ios/chrome/browser/ui/browser_view_controller_egtest.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.
 
 #include <map>
 
 #import <EarlGrey/EarlGrey.h>
 #import <WebKit/WebKit.h>
 #import <XCTest/XCTest.h>
 
@@ skipping 35 matching lines @@
   const GURL destinationURL =
       web::test::HttpServer::MakeUrl("http://destination");
   responses[startURL] = "Start";
   responses[destinationURL] = "You've arrived!";
   web::test::SetUpSimpleHttpServer(responses);
 
   // Just load the first URL.
   [ChromeEarlGrey loadURL:startURL];
 
   // Waits for the page to load and check it is the expected content.
-  id<GREYMatcher> responseMatcher =
-      chrome_test_util::WebViewContainingText(responses[startURL]);
-  [[EarlGrey selectElementWithMatcher:responseMatcher]
-      assertWithMatcher:grey_notNil()];
+  [ChromeEarlGrey waitForWebViewContainingText:responses[startURL]];
 
   // In the omnibox, the URL should be present, without the http:// prefix.
   [[EarlGrey selectElementWithMatcher:chrome_test_util::Omnibox()]
       assertWithMatcher:chrome_test_util::OmniboxText(startURL.GetContent())];
 
   // Types some javascript in the omnibox to trigger a navigation.
   NSString* script =
       [NSString stringWithFormat:@"javascript:location.href='%s'\n",
                                  destinationURL.spec().c_str()];
 
   [[EarlGrey selectElementWithMatcher:chrome_test_util::Omnibox()]
       performAction:grey_typeText(script)];
 
   // In the omnibox, the new URL should be present, without the http:// prefix.
   [[EarlGrey selectElementWithMatcher:chrome_test_util::Omnibox()]
       assertWithMatcher:chrome_test_util::OmniboxText(
                             destinationURL.GetContent())];
 
   // Verifies that the navigation to the destination page happened.
   GREYAssertEqual(destinationURL,
                   chrome_test_util::GetCurrentWebState()->GetVisibleURL(),
                   @"Did not navigate to the destination url.");
 
   // Verifies that the destination page is shown.
-  id<GREYMatcher> navigationMatcher =
-      chrome_test_util::WebViewContainingText(responses[destinationURL]);
-  [[EarlGrey selectElementWithMatcher:grey_kindOfClass([WKWebView class])]
-      assertWithMatcher:navigationMatcher];
+  [ChromeEarlGrey waitForWebViewContainingText:responses[destinationURL]];
 }
 
 @end