Expose way to enable/disable translate.

ios/web_view/internal/translate/cwv_translation_configuration_internal.h

Index: ios/web_view/internal/translate/cwv_translation_configuration_internal.h
diff --git a/ios/web_view/internal/translate/cwv_translation_configuration_internal.h b/ios/web_view/internal/translate/cwv_translation_configuration_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..81c1bb5f2968eeeec6c673b52cb127dd42bf6d72
--- /dev/null
+++ b/ios/web_view/internal/translate/cwv_translation_configuration_internal.h
@@ -0,0 +1,21 @@
+// 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_CONFIGURATION_H_
+#define IOS_WEB_VIEW_INTERNAL_TRANSLATE_CWV_TRANSLATION_CONFIGURATION_H_
+
+#import "ios/web_view/public/cwv_translation_configuration.h"
+
+class PrefService;
+
+// Internal methods to hide C++ details.

[Eugene But (OOO till 7-30), 2017/07/14 00:22:43]

nit: Do we need this comment? Technically category does not exist to hide C++
details, but to hide private initializer. 

[jzw1, 2017/07/14 02:09:49]

Done.

+@interface CWVTranslationConfiguration ()
+
+// Takes a PrefService object used to modify settings.

[Eugene But (OOO till 7-30), 2017/07/14 00:22:43]

Please document that callers are responsible for keeping |prefService| alive
until CWVTranslationConfiguration is alive.

[jzw1, 2017/07/14 02:09:49]

Done.

+- (instancetype)initWithPrefService:(PrefService*)prefService
+    NS_DESIGNATED_INITIALIZER;
+
+@end
+
+#endif  // IOS_WEB_VIEW_INTERNAL_TRANSLATE_CWV_TRANSLATION_CONFIGURATION_H_