Implement CWVWebView.scrollView.

ios/web_view/public/cwv_web_view.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_VIEW_PUBLIC_CWV_WEB_VIEW_H_
 #define IOS_WEB_VIEW_PUBLIC_CWV_WEB_VIEW_H_
 
 #import <ChromeWebView/cwv_export.h>
 #import <UIKit/UIKit.h>
 
+@class CWVScrollView;
 @class CWVWebViewConfiguration;
 @protocol CWVUIDelegate;
 @protocol CWVTranslateDelegate;
 @protocol CWVNavigationDelegate;
 
 // A web view component (like WKWebView) which uses iOS Chromium's web view
 // implementation.
 //
 // In addition to WKWebView features, it allows Translate, Find In Page,
 // Customizable Context Menus, and maybe more.
@@ skipping 30 matching lines @@
 // The current page title.
 @property(nonatomic, readonly, copy) NSString* title;
 
 // Page loading progress from 0.0 to 1.0. KVO compliant.
 //
 // It is 0.0 initially before the first navigation starts. After a navigation
 // completes, it remains at 1.0 until a new navigation starts, at which point it
 // is reset to 0.0.
 @property(nonatomic, readonly) double estimatedProgress;
 
+// The scroll view associated with the web view.
+@property(nonatomic, readonly) CWVScrollView* scrollView;
+
 // The User Agent product string used to build the full User Agent.
 + (NSString*)userAgentProduct;
 
 // Customizes the User Agent string by inserting |product|. It should be of the
 // format "product/1.0". For example:
 // "Mozilla/5.0 (iPhone; CPU iPhone OS 10_3 like Mac OS X) AppleWebKit/603.1.30
 // (KHTML, like Gecko) <product> Mobile/16D32 Safari/602.1" where <product>
 // will be replaced with |product| or empty string if not set.
 //
 // NOTE: It is recommended to set |product| before initializing any web views.
@@ skipping 35 matching lines @@
 - (void)loadRequest:(NSURLRequest*)request;
 
 // Evaluates a JavaScript string.
 // The completion handler is invoked when script evaluation completes.
 - (void)evaluateJavaScript:(NSString*)javaScriptString
          completionHandler:(void (^)(id, NSError*))completionHandler;
 
 @end
 
 #endif  // IOS_WEB_VIEW_PUBLIC_CWV_WEB_VIEW_H_