Expose method to reset translate settings.

ios/web_view/public/cwv_translation_controller.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_CONTROLLER_H
 #define IOS_WEB_VIEW_PUBLIC_CWV_TRANSLATION_CONTROLLER_H
 
 #import <Foundation/Foundation.h>
 
 #import "cwv_export.h"
@@ skipping 34 matching lines @@
 @interface CWVTranslationController : NSObject
 
 // Delegate to receive translation callbacks.
 @property(nullable, nonatomic, weak) id<CWVTranslationControllerDelegate>
     delegate;
 
 // The set of supported languages for translation.
 @property(nonatomic, readonly)
     NSSet<CWVTranslationLanguage*>* supportedLanguages;
 
+// Resets all translation policies to CWVTranslationPolicyAsk.

[Hiroshi Ichikawa, 2017/07/10 01:35:00]

Can you document that this method only clears the policies for
[CWVWebViewConfiguration defaultConfiguration], but not for
[CWVWebViewConfiguration incognitoConfiguration]?

Maybe we should also provide a way to clear the policies for incognito windows?
They are cleared when the app is terminated, but maybe we also want to clear the
incognito policies when the user explicitly asks to clear the policies?

[jzw1, 2017/07/10 03:21:31]

What if we clear both in this method? On second thought, maybe incognito users
shouldn't be able to configure any policies.

++ (void)resetTranslationPolicies;
+
 // Begins translation on the current page from |sourceLanguage| to
 // |targetLanguage|. These language parameters must be chosen from
 // |supportedLanguages|. Set |userInitiated| to YES if translation
 // is a result of explicit user action. |userInitiated| will be
 // passed along to the CWVTranslationControllerDelegate methods.
 // Results in a No-op if there is no current page.
 - (void)translatePageFromLanguage:(CWVTranslationLanguage*)sourceLanguage
                        toLanguage:(CWVTranslationLanguage*)targetLanguage
                     userInitiated:(BOOL)userInitiated;
 
@@ skipping 14 matching lines @@
 // |pageHost| should be the hostname of the website. Must not be empty.
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy
                  forPageHost:(NSString*)pageHost;
 - (CWVTranslationPolicy*)translationPolicyForPageHost:(NSString*)pageHost;
 
 @end
 
 NS_ASSUME_NONNULL_END
 
 #endif  // IOS_WEB_VIEW_PUBLIC_CWV_TRANSLATION_CONTROLLER_H