Remove CWV class and move setting User Agent to CWVWebViewConfiguration.

ios/web_view/shell/shell_view_controller.m

Index: ios/web_view/shell/shell_view_controller.m
diff --git a/ios/web_view/shell/shell_view_controller.m b/ios/web_view/shell/shell_view_controller.m
index 8e09be8868f276527075c674f2d510bb62c74f5b..39438be61e79aac540f9b023bac0366bbb2e9c2d 100644
--- a/ios/web_view/shell/shell_view_controller.m
+++ b/ios/web_view/shell/shell_view_controller.m
@@ -133,7 +133,12 @@ NSString* const kWebViewShellJavaScriptDialogTextFieldAccessibiltyIdentifier =
   [_toolbar addSubview:stop];
   [_toolbar addSubview:_field];
 
-  self.webView = [CWV webViewWithFrame:[_containerView bounds]];
+  [CWVWebView setUserAgentProduct:@"Dummy/1.0"];
+
+  CWVWebViewConfiguration* configuration =
+      [CWVWebViewConfiguration defaultConfiguration];
+  self.webView = [[CWVWebView alloc] initWithFrame:[_containerView bounds]
+                                     configuration:configuration];
   _webView.navigationDelegate = self;
   _webView.UIDelegate = self;
   _translateController = [[TranslateController alloc] init];