Implemented new Translate API for purely Objective-C clients.

ios/web_view/internal/translate/cwv_translation_controller_internal.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_INTERNAL_TRANSLATE_CWV_TRANSLATION_CONTROLLER_INTERNAL_H
+#define IOS_WEB_VIEW_INTERNAL_TRANSLATE_CWV_TRANSLATION_CONTROLLER_INTERNAL_H
+
+#import "ios/web_view/public/cwv_translation_controller.h"
+
+#include "components/translate/core/browser/translate_step.h"
+#include "components/translate/core/common/translate_errors.h"
+#import "ios/web/public/web_state/web_state.h"
+#import "ios/web_view/internal/translate/web_view_translate_client.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+// Some internal methods needed to hide any C++ details.
+@interface CWVTranslationController ()
+
+// Set to create a new translate stack under the new webState.
+@property(nonatomic, assign) web::WebState* webState;
+
+// Called by WebViewTranslateClient to pass on translation state.

[Eugene But (OOO till 7-30), 2017/04/28 03:07:29]

In the comments please do not document who calls this method (this interface
should not make such assumptions). Instead please explain the arguments and what
the method does.

[jzw1, 2017/04/28 05:43:36]

Done.

+- (void)updateTranslateStep:(translate::TranslateStep)step
+             sourceLanguage:(const std::string&)sourceLanguage
+             targetLanguage:(const std::string&)targetLanguage
+                  errorType:(translate::TranslateErrors::Type)errorType
+          triggeredFromMenu:(bool)triggeredFromMenu;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif  // IOS_WEB_VIEW_INTERNAL_TRANSLATE_CWV_TRANSLATION_CONTROLLER_INTERNAL_H