Remove CWV class and move setting User Agent to CWVWebViewConfiguration.

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 CWVWebViewConfiguration;
@@ skipping 36 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;
 
+// Customizes the User Agent string. It should be of the format "product/1.0".
+// NOTE: It is recommended to set |product| before initializing any web views.
+//
+// Setting |product| is only guaranteed to affect web views which have not yet
+// been initialized. However, exisiting web views could also be affected
+// depending upon their internal state.
++ (void)setUserAgentProduct:(NSString*)product;

[Eugene But (OOO till 7-30), 2017/04/08 00:34:36]

Should this be setUserAgent to allow better flexibility and API clarity? 

[michaeldo, 2017/04/11 17:07:48]

Per offline discussion, setUserAgentProduct should be sufficient. We can add an
additional API in the future if there is demand for it.

+
 // |configuration| must not be null
 - (instancetype)initWithFrame:(CGRect)frame
                 configuration:(CWVWebViewConfiguration*)configuration
     NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
 
 // Navigates backwards or forwards by one page.  Does nothing if the
 // corresponding |canGoBack| or |canGoForward| method returns NO.
@@ skipping 11 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_