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

ios/chrome/browser/ui/fullscreen_controller.h

 // Copyright 2013 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_FULLSCREEN_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_FULLSCREEN_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/web/public/web_state/crw_web_controller_observer.h"
@@ skipping 88 matching lines @@
 // matter what the scrollview is doing.
 - (void)disableFullScreen;
 // Enabling fullscreen will reverse the effect of a call to -disableFullScreen.
 // The toolbar will stay on screen until a move pushes it out.
 - (void)enableFullScreen;
 
 // Skip next attempt to correct the scroll offset for the toolbar height. This
 // is necessary when programatically scrolling down the y offset.
 - (void)shouldSkipNextScrollOffsetForHeader;
 
-// Update the insets during animation. When |forceUpdate| is set to NO, a faster
-// workaround implemention is used to update the content's offset.  That
-// implemention does not cause a full update. |forceUpdate| should only be set
-// to |NO| when -setToolbarInsetsForHeaderOffset is called
-// in quick succession during scroll callbacks.
-- (void)setToolbarInsetsForHeaderOffset:(CGFloat)headerOffset
-                            forceUpdate:(BOOL)forceUpdate;
+// Update the insets during animation.

[Eugene But (OOO till 7-30), 2016/12/21 18:48:43]

s/Update/Updates

[justincohen, 2016/12/21 19:59:45]

Done.

+- (void)setToolbarInsetsForHeaderOffset:(CGFloat)headerOffset;
 
 // Set the content offset of the underlying UIScrollView so that the content
 // is not hidden by the header. The header will be moved to its visible position
 // without animation if it is not already fully visible.
 - (void)moveContentBelowHeader;
 @end
 
 @interface FullScreenController (UsedForTesting)
 // Enables/Disables the FullScreenController in tests. The unit tests do not set
 // the delegate which is crucial for methods to work on the controller.
 // This a temporary solution.
 // TODO(shreyasv): Find a better solution/remove this when FullScreenController
 // moves to Tab.
 + (void)setEnabledForTests:(BOOL)enabled;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_FULLSCREEN_CONTROLLER_H_