Add CWVUserContentController which enables injecting JavaScripts.

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 <UIKit/UIKit.h>
 
 @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.
 //
 // Concrete instances can be created through CWV.
 @interface CWVWebView : UIView
 
+// The configuration of the web view.
+@property(nonatomic, readonly, copy) CWVWebViewConfiguration* configuration;
+
 // The view used to display web content.
 @property(nonatomic, readonly) UIView* view;
 
 // This web view's navigation delegate.
 @property(nonatomic, weak) id<CWVNavigationDelegate> navigationDelegate;
 
 // This web view's UI delegate
 @property(nonatomic, weak) id<CWVUIDelegate> UIDelegate;
 
 // A delegate for the translation feature.
@@ skipping 43 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_