Add CWVUserContentController which enables injecting JavaScripts.

ios/web_view/internal/cwv_user_content_controller_internal.h

Index: ios/web_view/internal/cwv_user_content_controller_internal.h
diff --git a/ios/web_view/internal/cwv_user_content_controller_internal.h b/ios/web_view/internal/cwv_user_content_controller_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..81eb4ee47919bf09ffce8980ec1a12bd4bee4c71
--- /dev/null
+++ b/ios/web_view/internal/cwv_user_content_controller_internal.h
@@ -0,0 +1,18 @@
+// Copyright 2017 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.

[michaeldo, 2017/03/21 16:12:34]

please add empty line after license, before header guard

[Hiroshi Ichikawa, 2017/03/22 04:52:52]

Done.

+#ifndef IOS_WEB_VIEW_PUBLIC_CWV_USER_CONTENT_CONTROLLER_INTERNAL_H_

[michaeldo, 2017/03/21 16:12:34]

s/PUBLIC/INTERNAL

IOS_WEB_VIEW_INTERNAL_CWV_USER_CONTENT_CONTROLLER_INTERNAL_H_

[Hiroshi Ichikawa, 2017/03/22 04:52:52]

Oops. Done.

+#define IOS_WEB_VIEW_PUBLIC_CWV_USER_CONTENT_CONTROLLER_INTERNAL_H_
+
+#import "ios/web_view/public/cwv_user_content_controller.h"
+
+@class CWVWebViewConfiguration;
+
+@interface CWVUserContentController ()
+
+- (instancetype)initWithConfiguration:
+    (__weak CWVWebViewConfiguration*)configuration;

[Eugene But (OOO till 7-30), 2017/03/21 16:47:55]

Do you want to specify that |configuration| is nonnull?

[Hiroshi Ichikawa, 2017/03/22 04:52:52]

Done. Added nonnull/nullable for other pointers in this class too.

[michaeldo, 2017/03/22 23:03:32]

Thanks for adding these, based on other classes, like UIView's header, this
initializer should return "nonnull instancetype". I believe nullable is usually
only used for initializers that could commonly return nil, like initWithCoder
methods. Even though initializers have the "if (self)"  check within their
implementation, I believe nonnull is the correct annotation for the return
value.

[Hiroshi Ichikawa, 2017/03/23 02:48:05]

Good to know, thanks. Done.

+
+@end
+
+#endif  // IOS_WEB_VIEW_PUBLIC_CWV_USER_CONTENT_CONTROLLER_INTERNAL_H_