Upstream the iOS web_shell and supporting code

ios/web/shell/view_controller.h

+// Copyright 2014 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_WEB_SHELL_VIEW_CONTROLLER_H_
+#define IOS_WEB_SHELL_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+#include "ios/web/public/web_state/crw_web_delegate.h"
+
+namespace web {
+class BrowserState;
+}
+
+// Implements the main UI for ios_web_shell, including a toolbar and web view.
+@interface ViewController
+    : UIViewController<CRWWebDelegate, UITextFieldDelegate>
+
+@property(nonatomic, retain) IBOutlet UIView* containerView;
+@property(nonatomic, retain) IBOutlet UIToolbar* toolbarView;
+
+// Initializes a new ViewController from |MainView.xib| using the given
+// |browserState|.
+- (instancetype)initWithBrowserState:(web::BrowserState*)browserState;
+
+@end
+
+#endif  // IOS_WEB_SHELL_VIEW_CONTROLLER_H_