Refactor web shell integration tests utilities.

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/shell_matchers.h"
+#import "ios/web/shell/test/earl_grey/shell_matchers.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 {
 
+// Shorthand for GREYMatchers::matcherForWebViewContainingText.
+id<GREYMatcher> webViewContainingText(NSString* text) {
+  return [GREYMatchers matcherForWebViewContainingText: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:(NSString*)text {
+  web::WebState* webState = web::web_shell_test_util::GetCurrentWebState();
+  return web::webViewContainingText(text, webState);
+}
+
 + (id<GREYMatcher>)matcherForWebShellBackButton {
   return grey_accessibilityLabel(kWebShellBackButtonAccessibilityLabel);
 }
 
 + (id<GREYMatcher>)matcherForWebShellForwardButton {
   return grey_accessibilityLabel(kWebShellForwardButtonAccessibilityLabel);
 }
 
 + (id<GREYMatcher>)matcherForWebShellAddressField {
   return grey_accessibilityLabel(kWebShellAddressFieldAccessibilityLabel);
 }
 
 @end