Revert "[ios] Disables failing iOS12 tests while EG team investigates."

This reverts commit 155b67d6.

Reason for revert: Test fix in latest EG.

Original change's description:
> [ios] Disables failing iOS12 tests while EG team investigates.
> 
> It seems with Xcode 10 items behind the keyboard are appearing as visible.
> This is likely an EG bug.
> 
> Bug: 854847
> Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
> Change-Id: I905d4e7809afe6d5d35e240b8e6c815f70cd41df
> Reviewed-on: https://chromium-review.googlesource.com/1109307
> Reviewed-by: Gauthier Ambard <gambard@chromium.org>
> Reviewed-by: Sergio Collazos <sczs@chromium.org>
> Commit-Queue: Justin Cohen <justincohen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#569242}

TBR=rohitrao@chromium.org,justincohen@chromium.org,sczs@chromium.org,gambard@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 854847
Change-Id: I5c1253288d99291fbd5e1677a6a0fb57c3142ffe
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Reviewed-on: https://chromium-review.googlesource.com/1185801Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585247}

ios/chrome/browser/ui/toolbar/adaptive/adaptive_toolbar_egtest.mm

@@ -5,7 +5,6 @@
 #import <EarlGrey/EarlGrey.h>
 #import <XCTest/XCTest.h>
 
-#include "base/ios/ios_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/infobars/infobar_manager_impl.h"
@@ -477,11 +476,6 @@ void FocusOmnibox() {
 // Check the button visibility of the toolbar when the omnibox is focused from a
 // different orientation than the default one.
 - (void)testFocusOmniboxFromOtherOrientation {
-  // TODO(crbug.com/854847) Re-enable these tests once EG bug is fixed.
-  if (base::ios::IsRunningOnIOS12OrLater()) {
-    EARL_GREY_TEST_DISABLED(@"Test disabled on iOS 12.");
-  }
-
   // Load a page to have the toolbar visible (hidden on NTP).
   [ChromeEarlGrey loadURL:GURL("chrome://version")];
 
@@ -520,10 +514,6 @@ void FocusOmnibox() {
 // Check the button visibility of the toolbar when the omnibox is focused from
 // the default orientation.
 - (void)testFocusOmniboxFromPortrait {
-  // TODO(crbug.com/854847) Re-enable these tests once EG bug is fixed.
-  if (base::ios::IsRunningOnIOS12OrLater()) {
-    EARL_GREY_TEST_DISABLED(@"Test disabled on iOS 12.");
-  }
   // Load a page to have the toolbar visible (hidden on NTP).
   [ChromeEarlGrey loadURL:GURL("chrome://version")];