[ios] Disables testInputAccessoryViewNavigationButtons on iOS 11.

This test was already disabled on iOS 11 iPad, but it has started failing on
iPhone as well in the iOS 11 GM build.

BUG=753098

Change-Id: I7abf2cf6bc0a4547abfbcd5e0193903dd3f55d83
Reviewed-on: https://chromium-review.googlesource.com/664837
Commit-Queue: Rohit Rao (ping after 24h) <[email protected]>
Commit-Queue: Justin Cohen <[email protected]>
Reviewed-by: Olivier Robin <[email protected]>
Reviewed-by: Justin Cohen <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#501604}(cherry picked from commit 9ca5963)
Reviewed-on: https://chromium-review.googlesource.com/679294
Reviewed-by: Moe Ahmadi <[email protected]>
Cr-Commit-Position: refs/branch-heads/3202@{crosswalk-project#402}
Cr-Branched-From: fa6a5d8-refs/heads/master@{#499098}

ios/showcase/payments/sc_payments_editor_egtest.mm

@@ -209,8 +209,9 @@ - (void)testInputAccessoryViewCloseButton {
 // navigate between the textfields.
 - (void)testInputAccessoryViewNavigationButtons {
   // TODO(crbug.com/753098): Re-enable this test on iOS 11 iPad once
-  // grey_typeText works on iOS 11.
-  if (base::ios::IsRunningOnIOS11OrLater() && IsIPadIdiom()) {
+  // grey_typeText works on iOS 11.  The test failes on iOS 11 iPhone as well,
+  // but possibly for a different reason.
+  if (base::ios::IsRunningOnIOS11OrLater()) {
     EARL_GREY_TEST_DISABLED(@"Test disabled on iOS 11.");
   }