Added translation policy API.

ios/web_view/internal/translate/cwv_translation_policy.mm

Index: ios/web_view/internal/translate/cwv_translation_policy.mm
diff --git a/ios/web_view/internal/translate/cwv_translation_policy.mm b/ios/web_view/internal/translate/cwv_translation_policy.mm
new file mode 100644
index 0000000000000000000000000000000000000000..475a0811e702273d9b45811832a25b293245bf60
--- /dev/null
+++ b/ios/web_view/internal/translate/cwv_translation_policy.mm
@@ -0,0 +1,38 @@
+// 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.
+
+#import "ios/web_view/public/cwv_translation_policy.h"
+
+#import "ios/web_view/public/cwv_translation_language.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation CWVTranslationPolicy
+
+@synthesize language = _language;
+@synthesize type = _type;
+
++ (CWVTranslationPolicy*)translationPolicyAsk {
+  CWVTranslationPolicy* policy = [[CWVTranslationPolicy alloc] init];
+  policy->_type = CWVTranslationPolicyAsk;

[Eugene But (OOO till 7-30), 2017/05/11 15:48:59]

alloc/init can return null and this will crash. Do you want to add a private
initWithPolicyType:language: init?

[jzw1, 2017/05/12 03:46:46]

Done.

+  return policy;
+}
+
++ (CWVTranslationPolicy*)translationPolicyNever {
+  CWVTranslationPolicy* policy = [[CWVTranslationPolicy alloc] init];
+  policy->_type = CWVTranslationPolicyNever;

[michaeldo, 2017/05/11 23:51:33]

Can you use synthesized setters instead? I don't know if this style is common.
|setType:| will work if you re-defined property as readwrite in this file.

[jzw1, 2017/05/12 03:46:46]

Done.

+  return policy;
+}
+
++ (CWVTranslationPolicy*)translationPolicyAutoTranslateToLanguage:
+    (CWVTranslationLanguage*)language {
+  CWVTranslationPolicy* policy = [[CWVTranslationPolicy alloc] init];
+  policy->_type = CWVTranslationPolicyAuto;
+  policy->_language = language;
+  return policy;
+}
+
+@end