Create ChromeEarlGrey waitForWebViewContainingText.

ios/chrome/test/earl_grey/chrome_earl_grey.mm

Index: ios/chrome/test/earl_grey/chrome_earl_grey.mm
diff --git a/ios/chrome/test/earl_grey/chrome_earl_grey.mm b/ios/chrome/test/earl_grey/chrome_earl_grey.mm
index 970abc0bfd4276df1e472516718046323abc77de..2db43509709827bedc4bc17dd22c3c287d38eea8 100644
--- a/ios/chrome/test/earl_grey/chrome_earl_grey.mm
+++ b/ios/chrome/test/earl_grey/chrome_earl_grey.mm
@@ -21,6 +21,7 @@
 #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"
@@ -184,4 +185,15 @@ id ExecuteJavaScript(NSString* javascript,
              @"Failed, there was a static html view containing %@", text);
 }
 
++ (void)waitForWebViewContainingText:(NSString*)text {
+  GREYCondition* condition =
+      [GREYCondition conditionWithName:@"Wait for web view containing text"
+                                 block:^BOOL {
+                                   return web::test::WebViewContainingText(
+                                       chrome_test_util::GetCurrentWebState(),
+                                       base::SysNSStringToUTF8(text));
+                                 }];
+  GREYAssert([condition waitWithTimeout:testing::kWaitForUIElementTimeout],
+             @"Failed waiting for web view containing %@", text);
+}
 @end