Add wait to testBrowsingPostEntryWithKeyboard.

ios/chrome/browser/web/browsing_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.
 
 #import <XCTest/XCTest.h>
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/ios/ios_util.h"
@@ skipping 561 matching lines @@
   // forward again.
   [self goBack];
   [[EarlGrey selectElementWithMatcher:OmniboxText(firstURL.GetContent())]
       assertWithMatcher:grey_notNil()];
   [self goForward];
   [[EarlGrey selectElementWithMatcher:OmniboxText(secondURL.GetContent())]
       assertWithMatcher:grey_notNil()];
 }
 
 // Tap the text field indicated by |ID| to open the keyboard, and then
-// press the keyboard's "Go" button.
-- (void)openKeyboardAndTapGoButtonWithTextFieldID:(const std::string&)ID {
+// press the keyboard's "Go" button to submit the form.
+- (void)submitFormUsingKeyboardGoButtonWithInputID:(const std::string&)ID {
   // Disable EarlGrey's synchronization since it is blocked by opening the
   // keyboard from a web view.
   [[GREYConfiguration sharedInstance]
           setValue:@NO
       forConfigKey:kGREYConfigKeySynchronizationEnabled];
 
   // Wait for web view to be interactable before tapping.
   GREYCondition* interactableCondition = [GREYCondition
       conditionWithName:@"Wait for web view to be interactable."
                   block:^BOOL {
@@ skipping 26 matching lines @@
   GREYAssert([condition waitWithTimeout:10],
              @"No keyboard with 'Go' button showed up.");
 
   [[EarlGrey selectElementWithMatcher:grey_accessibilityID(@"Go")]
       performAction:grey_tap()];
 
   // Reenable synchronization now that the keyboard has been closed.
   [[GREYConfiguration sharedInstance]
           setValue:@YES
       forConfigKey:kGREYConfigKeySynchronizationEnabled];
+
+  // Ensure that the new page loaded before continuing.
+  [ChromeEarlGrey waitForPageToFinishLoading];
 }
 
 // Tests that submitting a POST-based form by tapping the 'Go' button on the
 // keyboard navigates to the correct URL and the back button works as expected
 // afterwards.
 // TODO(crbug.com/704618): Re-enable this test when the flake is fixed.
 - (void)FLAKY_testBrowsingPostEntryWithKeyboard {
   // Create map of canned responses and set up the test HTML server.
   std::map<GURL, std::string> responses;
   const GURL URL =
       web::test::HttpServer::MakeUrl("http://postEntryWithKeyboard");
   const GURL destinationURL = web::test::HttpServer::MakeUrl("http://foo");
   // This is a page this an input text field and a button that posts to the
   // destination.
   responses[URL] = base::StringPrintf(
       "hello!"
       "<form action='%s' method='post'>"
       "<input value='textfield' id='textfield' type='text'></label>"
       "<input type='submit'></form>",
       destinationURL.spec().c_str());
   // This is the page that should be showing at the end of the test.
   responses[destinationURL] = "baz!";
   web::test::SetUpSimpleHttpServer(responses);
 
   // Open the URL, focus the textfield,and submit via keyboard.
   [ChromeEarlGrey loadURL:URL];
   [[EarlGrey selectElementWithMatcher:WebViewContainingText("hello!")]
       assertWithMatcher:grey_notNil()];
 
-  [self openKeyboardAndTapGoButtonWithTextFieldID:"textfield"];
+  [self submitFormUsingKeyboardGoButtonWithInputID:"textfield"];
 
   // Verify that the browser navigates to the expected URL.
   [[EarlGrey selectElementWithMatcher:OmniboxText(destinationURL.GetContent())]
       assertWithMatcher:grey_notNil()];
 
   // Go back and verify that the browser navigates to the original URL.
   [self goBack];
   [[EarlGrey selectElementWithMatcher:OmniboxText(URL.GetContent())]
       assertWithMatcher:grey_notNil()];
 }
 
 @end