Add tests against pressing tab when a view controller is presented

ios/chrome/browser/ui/settings/settings_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 <EarlGrey/EarlGrey.h>
 #import <UIKit/UIKit.h>
 #import <XCTest/XCTest.h>
 #include <map>
 
 #include "base/bind.h"
@@ skipping 248 matching lines @@
             kTestOrigin1, &dummy_key, base::Bind(CertCallback));
         dispatch_semaphore_signal(semaphore);
       }));
   dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
   dispatch_release(semaphore);
   return result == net::ERR_FILE_NOT_FOUND;
 }
 
 }  // namespace
 
+// Expose the first responder.
+@interface UIWindow (FirstResponder)
+- (UIResponder*)firstResponder;
+@end
+
 // Settings tests for Chrome.
 @interface SettingsTestCase : ChromeTestCase
 @end
 
 @implementation SettingsTestCase
 
 // Opens the a submenu from the settings page.  Must be called from the NTP.
 // TODO(crbug.com/684619): Investigate why usingSearchAction doesn't scroll
 // until the bottom.
 - (void)openSubSettingMenu:(id<GREYMatcher>)settingToTap {
@@ skipping 668 matching lines @@
 - (void)testAccessibilityOnPasswords {
   [ChromeEarlGreyUI openToolsMenu];
   [[EarlGrey selectElementWithMatcher:SettingsButton()]
       performAction:grey_tap()];
   [[EarlGrey selectElementWithMatcher:PasswordsButton()]
       performAction:grey_tap()];
   chrome_test_util::VerifyAccessibilityForCurrentScreen();
   [self closeSubSettingsMenu];
 }
 
+// Tests that hitting the tab key doesn't trigger the omnibox in the background.
+// Testing against regressions of the fix for crbug.com/676993.
+- (void)testTabKeyIsANoOp {
+  // Open Settings.
+  [ChromeEarlGreyUI openToolsMenu];
+  [[EarlGrey selectElementWithMatcher:SettingsButton()]
+      performAction:grey_tap()];
+
+  // Hit the tab key.
+  // TODO(crbug.com/695876): Simulate a tab key press with EalrGrey.
+
+  // Verify that the omnibox is not focused.
+  GREYAssertFalse([[[[UIApplication sharedApplication] keyWindow]
+      firstResponder] isKindOfClass:[UITextField class]]);
+}
+
 @end