Revert to the old back arrow style with NavigationBar

ios/chrome/browser/ui/settings/block_popups_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 "base/ios/ios_util.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 63 matching lines @@
       performAction:grey_tap()];
 
   [[EarlGrey selectElementWithMatcher:block_popups_button_matcher]
       performAction:grey_tap()];
 }
 
 // Exits out of settings.  Must be called from the block popups settings page.
 void CloseSettings() {
   [[EarlGrey
       selectElementWithMatcher:grey_allOf(
-                                   grey_accessibilityID(@"back_bar_button"),
+                                   grey_accessibilityID(@"ic_arrow_back"),
                                    grey_accessibilityTrait(
                                        UIAccessibilityTraitButton),
                                    nil)] performAction:grey_tap()];
   [[EarlGrey
       selectElementWithMatcher:grey_allOf(
-                                   grey_accessibilityID(@"back_bar_button"),
+                                   grey_accessibilityID(@"ic_arrow_back"),
                                    grey_accessibilityTrait(
                                        UIAccessibilityTraitButton),
                                    nil)] performAction:grey_tap()];
   [[EarlGrey
       selectElementWithMatcher:chrome_test_util::buttonWithAccessibilityLabelId(
                                    IDS_IOS_NAVIGATION_BAR_DONE_BUTTON)]
       performAction:grey_tap()];
 }
 
 // ScopedBlockPopupsPref modifies the block popups preference and resets the
@@ skipping 190 matching lines @@
       assertWithMatcher:grey_sufficientlyVisible()];
   [[EarlGrey
       selectElementWithMatcher:grey_accessibilityLabel(l10n_util::GetNSString(
                                    IDS_IOS_NAVIGATION_BAR_EDIT_BUTTON))]
       assertWithMatcher:grey_sufficientlyVisible()];
 
   CloseSettings();
 }
 
 @end