Revert "iOS 11 WKWebView load is broken"

This reverts commit 28dfaa0d.

Reason for revert: This appears fixed in Xcode 9 beta 4.

Original change's description:
> iOS 11 WKWebView load is broken
> 
> In iOS 11, WKWebView has issues (time outs) when loading request if the
> view is not part of the hierarchy. The WKWebView is now added to the
> hierarchy but off screen.
> 
> Bug: 738435, 739390
> Change-Id: Ica8584c30a24a11c04658774bd22a77273a93514
> Reviewed-on: https://chromium-review.googlesource.com/577807
> Commit-Queue: Jérôme Lebel <jlebel@chromium.org>
> Reviewed-by: Rohit Rao <rohitrao@chromium.org>
> Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
> Reviewed-by: Eugene But <eugenebut@chromium.org>
> Reviewed-by: Justin Cohen <justincohen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#488213}

TBR=rohitrao@chromium.org,msarda@chromium.org,justincohen@chromium.org,eugenebut@chromium.org,jlebel@chromium.org

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

Bug: 738435, 739390
Change-Id: Ic57820325fef5ac86b93b4f02f449b97f0b458e0
Reviewed-on: https://chromium-review.googlesource.com/591671Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Benoit Zanotti <bzanotti@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490743}

components/signin/ios/browser/account_consistency_service.mm

@@ -6,7 +6,6 @@
 
 #import <WebKit/WebKit.h>
 
-#include "base/ios/ios_util.h"
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #include "base/macros.h"
@@ -395,15 +394,6 @@ WKWebView* AccountConsistencyService::GetWKWebView() {
   }
   if (!web_view_) {
     web_view_ = BuildWKWebView();
-    if (base::ios::IsRunningOnIOS11OrLater()) {
-      // On iOS 11 WKWebView load is broken if view is not a part of the
-      // hierarchy. Add view to the hierarchy, but place it offscreen to
-      // workaround iOS bug (rdar://33184203 and crbug.com/738435)
-      // TODO(crbug.com/739390): Remove this workaround.
-      web_view_.hidden = YES;
-      web_view_.frame = CGRectMake(-100, -100, 100, 100);
-      [UIApplication.sharedApplication.keyWindow addSubview:web_view_];
-    }
     navigation_delegate_ = [[AccountConsistencyNavigationDelegate alloc]
         initWithCallback:base::Bind(&AccountConsistencyService::
                                         FinishedApplyingCookieRequest,
@@ -420,13 +410,6 @@ WKWebView* AccountConsistencyService::BuildWKWebView() {
 void AccountConsistencyService::ResetWKWebView() {
   [web_view_ setNavigationDelegate:nil];
   [web_view_ stopLoading];
-  if (base::ios::IsRunningOnIOS11OrLater()) {
-    // On iOS 11 WKWebView load is broken if view is not a part of the
-    // hierarchy. Add view to the hierarchy, but place it offscreen to
-    // workaround iOS bug (rdar://33184203 and crbug.com/738435)
-    // TODO(crbug.com/739390): Remove this workaround.
-    [web_view_ removeFromSuperview];
-  }
   web_view_ = nil;
   navigation_delegate_ = nil;
   applying_cookie_requests_ = false;