Stop re-adding subviews to keyboard accessory view.

ios/chrome/browser/ui/toolbar/new_keyboard_accessory_view.mm

 // Copyright 2017 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/toolbar/new_keyboard_accessory_view.h"
 
 #import <NotificationCenter/NotificationCenter.h>
 
 #include "base/mac/foundation_util.h"
 #include "ios/chrome/browser/experimental_flags.h"
@@ skipping 25 matching lines @@
 @implementation NewKeyboardAccessoryView
 
 // Unused by this implementation of |KeyboardAccessoryViewProtocol|.
 @synthesize mode = _mode;
 
 @synthesize buttonTitles = _buttonTitles;
 @synthesize delegate = _delegate;
 
 - (instancetype)initWithButtons:(NSArray<NSString*>*)buttonTitles
                        delegate:(id<KeyboardAccessoryViewDelegate>)delegate {
-  DCHECK(!IsIPadIdiom());
-
   const CGFloat kViewHeight = 44.0;
   CGFloat width = [[UIScreen mainScreen] bounds].size.width;
   // TODO(734512): Have the creator of the view define the size.
   CGRect frame = CGRectMake(0.0, 0.0, width, kViewHeight);
 
   self = [super initWithFrame:frame inputViewStyle:UIInputViewStyleKeyboard];
   if (self) {
     _buttonTitles = buttonTitles;
     _delegate = delegate;
-
+    [self addSubviews];
   }
   return self;
 }
 
-- (void)willMoveToSuperview:(UIView*)newSuperview {
+- (void)addSubviews {
   if (!self.subviews.count)
     return;
 
   const CGFloat kButtonMinWidth = 36.0;
   const CGFloat kButtonHeight = 34.0;
   const CGFloat kBetweenShortcutButtonSpacing = 5.0;
   const CGFloat kBetweenSearchButtonSpacing = 12.0;
   const CGFloat kMarginFromBottom = 2.0;
   const CGFloat kHorizontalMargin = 12.0;
 
@@ skipping 103 matching lines @@
   return YES;
 }
 
 - (void)keyboardButtonPressed:(id)sender {
   UIButton* button = base::mac::ObjCCastStrict<UIButton>(sender);
   [[UIDevice currentDevice] playInputClick];
   [_delegate keyPressed:[button currentTitle]];
 }
 
 @end