Revert 'Bypass UIWebView.scrollView's contentInset implementation with UIScrollView's.

ios/chrome/browser/ui/browser_view_controller.mm

 // Copyright 2012 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 "ios/chrome/browser/ui/browser_view_controller.h"
 
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <PassKit/PassKit.h>
 #import <Photos/Photos.h>
@@ skipping 2624 matching lines @@
 
   CGFloat footerHeight = CGRectGetHeight(footer.frame);
   CGFloat offset = headerOffset * footerHeight / headerHeight;
   return std::ceil(CGRectGetHeight(self.view.bounds) - footerHeight + offset);
 }
 
 - (void)fullScreenController:(FullScreenController*)controller
     headerAnimationCompleted:(BOOL)completed
                       offset:(CGFloat)offset {
   if (completed)
-    [controller setToolbarInsetsForHeaderOffset:offset forceUpdate:YES];
+    [controller setToolbarInsetsForHeaderOffset:offset];
 }
 
 - (void)setFramesForHeaders:(const std::vector<HeaderDefinition>)headers
                    atOffset:(CGFloat)headerOffset {
   CGFloat height = [self headerOffset];
   for (const auto& header : headers) {
     CGRect frame = [header.view frame];
     frame.origin.y = height - headerOffset - header.inset;
     [header.view setFrame:frame];
     if (header.behaviour != Overlap)
@@ skipping 2433 matching lines @@
 
 - (UIView*)voiceSearchButton {
   return _voiceSearchButton;
 }
 
 - (id<LogoAnimationControllerOwner>)logoAnimationControllerOwner {
   return [self currentLogoAnimationControllerOwner];
 }
 
 @end