Add wait to testBrowsingPostEntryWithKeyboard.

ios/chrome/browser/web/browsing_egtest.mm

Index: ios/chrome/browser/web/browsing_egtest.mm
diff --git a/ios/chrome/browser/web/browsing_egtest.mm b/ios/chrome/browser/web/browsing_egtest.mm
index a134f5b1983d82db9f3f647d9ebba49ee8968832..1e82fe6a8493e4fd0afb48c7242e9df1dc4ab6c6 100644
--- a/ios/chrome/browser/web/browsing_egtest.mm
+++ b/ios/chrome/browser/web/browsing_egtest.mm
@@ -627,6 +627,9 @@ id<GREYMatcher> GoButtonMatcher() {
   [[GREYConfiguration sharedInstance]
           setValue:@YES
       forConfigKey:kGREYConfigKeySynchronizationEnabled];
+
+  // Ensure that the new page loaded before continuing.
+  [ChromeEarlGrey waitForPageToFinishLoading];

[Eugene But (OOO till 7-30), 2017/04/05 04:52:41]

According to API contract this method just enters the text and taps Go. It's not
suppose to wait for page load or even know that Go initiates a form submission.
Do you want to move this wait call to the test instead?

[gchatz, 2017/04/05 23:43:53]

In order for Go to be in the keyboard, the textfield is linked to a form
submission. I would prefer to just specify this in the comments, and leave the
wait here. 

[Eugene But (OOO till 7-30), 2017/04/06 00:28:18]

The method name is |openKeyboardAndTapGoButtonWithTextFieldID:|, so it does not
imply form submission or waiting for the load to finish. If you want this method
to wait, then how about renaming it to reflect it's actual functionality (form
submission)?

 }
 
 // Tests that submitting a POST-based form by tapping the 'Go' button on the