Fix PasswordsSettingsTestCase.testCopyPasswordToast

ios/chrome/browser/ui/settings/passwords_settings_egtest.mm

Index: ios/chrome/browser/ui/settings/passwords_settings_egtest.mm
diff --git a/ios/chrome/browser/ui/settings/passwords_settings_egtest.mm b/ios/chrome/browser/ui/settings/passwords_settings_egtest.mm
index d3ec529a471b19997416d43f6bbb14c64a625438..669cc9232699f247d29ca08d16f2b9a6cb11749d 100644
--- a/ios/chrome/browser/ui/settings/passwords_settings_egtest.mm
+++ b/ios/chrome/browser/ui/settings/passwords_settings_egtest.mm
@@ -339,8 +339,7 @@ id<GREYMatcher> CopyPasswordButton() {
 
 // Checks that attempts to copy a password provide appropriate feedback,
 // both when reauthentication succeeds and when it fails.
-// TODO(crbug.com/718043): Re-enable test.
-- (void)DISABLED_testCopyPasswordToast {
+- (void)testCopyPasswordToast {
   [self scopedEnablePasswordManagementAndViewingUI];
 
   // Saving a form is needed for using the "password details" view.
@@ -373,8 +372,13 @@ id<GREYMatcher> CopyPasswordButton() {
   [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
   NSString* snackbarLabel =
       l10n_util::GetNSString(IDS_IOS_SETTINGS_PASSWORD_WAS_COPIED_MESSAGE);
+  // Tap the label instead of asserting that it is there, and wait until the
+  // tap causes it to close. Otherwise it will block the copy button for the
+  // rest of the test on small devices, and scrolling to reach the button
+  // won't work when the snackbar is up.
   [[EarlGrey selectElementWithMatcher:grey_accessibilityLabel(snackbarLabel)]
-      assertWithMatcher:grey_notNil()];
+      performAction:grey_tap()];
+  [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];

[baxley, 2017/05/03 18:07:11]

Does this guarantee that the snackbar is gone when the drain is complete? Or
does this act as more of a sleep?

If it's the former, then I think it's fine. If it's the latter, this can become
a source of flake and would prefer waiting for some state that we know we would
reach when the snackbar is gone.

[vabr (Chromium), 2017/05/03 20:32:26]

I have good news. When I caused the fade-out animation to take 5 seconds instead
of the usual 0.5 (by adjusting MDCSnackbarTransitionDuration in
ios/third_party/material_components_ios/src/components/Snackbar/src/private/MDCSnackbarOverlayView.m
, the test still patiently waited for the animation to complete before
continuing (and it passed). So it seems that drainUntilIdle indeed waits until
the snackbar is gone.

 
   // Check the snackbar in case of failed reauthentication.
   mock_reauthentication_module.shouldSucceed = NO;