Implemented new Translate API for purely Objective-C clients.

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 c7b1b2a059774c8636317fa655ca9ca23b22540f..3517766a9e0679cec7ede25cd5e73eb96f7becb1 100644
--- a/ios/web_view/shell/shell_view_controller.m
+++ b/ios/web_view/shell/shell_view_controller.m
@@ -156,7 +156,7 @@ NSString* const kWebViewShellJavaScriptDialogTextFieldAccessibiltyIdentifier =
   _webView.navigationDelegate = self;
   _webView.UIDelegate = self;
   _translateController = [[TranslateController alloc] init];

[Hiroshi Ichikawa, 2017/04/26 08:40:57]

Can you maybe rename this class and the variable name to _translateDelegate or
something? It's confusing with _webView.translationController now.

[jzw1, 2017/04/27 04:54:02]

Done.

-  _webView.translationDelegate = _translateController;
+  _webView.translationController.delegate = _translateController;
 
   [_webView setAutoresizingMask:UIViewAutoresizingFlexibleWidth |
                                 UIViewAutoresizingFlexibleHeight];