Remove CWV class and move setting User Agent to CWVWebViewConfiguration.

ios/web_view/shell/shell_app_delegate.m

Index: ios/web_view/shell/shell_app_delegate.m
diff --git a/ios/web_view/shell/shell_app_delegate.m b/ios/web_view/shell/shell_app_delegate.m
index a553363fdfc5d2fc3cba826da0ea3cd2782188eb..b1b2e5e035a38a3b7a57f2b345f83839a089a5a8 100644
--- a/ios/web_view/shell/shell_app_delegate.m
+++ b/ios/web_view/shell/shell_app_delegate.m
@@ -4,8 +4,6 @@
 
 #import "ios/web_view/shell/shell_app_delegate.h"
 
-#import <ChromeWebView/ChromeWebView.h>
-
 #import "ios/web_view/shell/shell_view_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -25,8 +23,6 @@
   self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
   self.window.backgroundColor = [UIColor whiteColor];
 
-  [CWV configureWithUserAgentProductName:@"Dummy/1.0"];
-
   ShellViewController* controller = [[ShellViewController alloc] init];
   // Gives a restoration identifier so that state restoration works.
   controller.restorationIdentifier = @"rootViewController";