Remove legacy InfoBarViewProtocol.

ios/chrome/browser/ui/infobars/infobar_view.mm

 // Copyright (c) 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/infobars/infobar_view.h"
 
 #import <CoreGraphics/CoreGraphics.h>
 #import <QuartzCore/QuartzCore.h>
 
 #include "base/format_macros.h"
@@ skipping 240 matching lines @@
   // button1_ is tagged with ConfirmInfoBarDelegate::BUTTON_OK .
   // button2_ is tagged with ConfirmInfoBarDelegate::BUTTON_CANCEL .
   base::scoped_nsobject<UIButton> button1_;
   base::scoped_nsobject<UIButton> button2_;
   // Drop shadow.
   base::scoped_nsobject<UIImageView> shadow_;
 }
 
 @synthesize visibleHeight = visibleHeight_;
 
-- (id)initWithFrame:(CGRect)frame delegate:(InfoBarViewDelegate*)delegate {
+- (instancetype)initWithFrame:(CGRect)frame
+                     delegate:(InfoBarViewDelegate*)delegate {
   self = [super initWithFrame:frame];
   if (self) {
     delegate_ = delegate;
     // Make the drop shadow.
     UIImage* shadowImage = [UIImage imageNamed:@"infobar_shadow"];
     shadow_.reset([[UIImageView alloc] initWithImage:shadowImage]);
     [self addSubview:shadow_];
     [self setAutoresizingMask:UIViewAutoresizingFlexibleWidth |
                               UIViewAutoresizingFlexibleHeight];
     [self setAccessibilityViewIsModal:YES];
@@ skipping 670 matching lines @@
 
 - (CGFloat)buttonMargin {
   return kButtonMargin;
 }
 
 - (const std::vector<std::pair<NSUInteger, NSRange>>&)linkRanges {
   return linkRanges_;
 }
 
 @end