Added translation policy API.

ios/web_view/public/cwv_translation_policy.h

+// 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.
+
+#ifndef IOS_WEB_VIEW_PUBLIC_CWV_TRANSLATION_POLICY_H
+#define IOS_WEB_VIEW_PUBLIC_CWV_TRANSLATION_POLICY_H
+
+#import <ChromeWebView/cwv_export.h>
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class CWVTranslationLanguage;
+
+typedef NS_ENUM(NSInteger, CWVTranslationPolicyType) {
+  CWVTranslationPolicyAsk,    // Prompt user on whether or not to translate.
+  CWVTranslationPolicyNever,  // Never translate.
+  CWVTranslationPolicyAuto    // Automatically translate according to policy.
+};
+
+// Represents a translation policy that can associated with another object like
+// a language or website hostname.
+CWV_EXPORT
+@interface CWVTranslationPolicy : NSObject
+
+// Convenience constructors.
++ (CWVTranslationPolicy*)translationPolicyAsk;
++ (CWVTranslationPolicy*)translationPolicyNever;
++ (CWVTranslationPolicy*)translationPolicyAutoTranslateToLanguage:
+    (CWVTranslationLanguage*)language;
+
+// Policy type.
+@property(nonatomic, readonly) CWVTranslationPolicyType type;
+
+// Nil unless |type| is CWVTranslationPolicyAuto.

[Hiroshi Ichikawa, 2017/05/10 08:36:56]

Can you add a comment that this is the language it auto-translates to?

Optional: Also, it may be clearer if the property name is targetLanguage
instead?

[jzw1, 2017/05/11 03:03:17]

I'll just add some cmoments.

+@property(nonatomic, readonly) CWVTranslationLanguage* language;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif  // IOS_WEB_VIEW_PUBLIC_CWV_TRANSLATION_POLICY_H