Added translation policy API.

components/translate/core/browser/translate_ui_delegate.h

Index: components/translate/core/browser/translate_ui_delegate.h
diff --git a/components/translate/core/browser/translate_ui_delegate.h b/components/translate/core/browser/translate_ui_delegate.h
index 230a68cd6c973319c5dc5c44c80408990aae1294..4d49a284e85222e0a94df63869e1a12b7e8fd2c3 100644
--- a/components/translate/core/browser/translate_ui_delegate.h
+++ b/components/translate/core/browser/translate_ui_delegate.h
@@ -77,6 +77,9 @@ class TranslateUIDelegate {
   // Returns the ISO code for the language at |index|.
   std::string GetLanguageCodeAt(size_t index) const;
 
+  // Returns the index of |language_code|.
+  size_t GetLanguageIndex(const std::string& language_code);
+
   // Returns the displayable name for the language at |index|.
   base::string16 GetLanguageNameAt(size_t index) const;
 
@@ -101,15 +104,27 @@ class TranslateUIDelegate {
   // Returns true if the current language is blocked.
   bool IsLanguageBlocked();
 
+  // Returns true if |language_code| is blocked.
+  bool IsLanguageBlocked(const std::string& language_code);
+
   // Sets the value if the current language is blocked.
   void SetLanguageBlocked(bool value);
 
+  // Sets the value if the |language_code| is blocked.
+  void SetLanguageBlocked(bool value, const std::string& language_code);
+
   // Returns true if the current webpage is blacklisted.
   bool IsSiteBlacklisted();
 
+  // Returns true if |page_host| is blacklisted.
+  bool IsSiteBlacklisted(const std::string& page_host);
+
   // Sets the value if the current webpage is blacklisted.
   void SetSiteBlacklist(bool value);
 
+  // Sets the value if the |page_host| is blacklisted.
+  void SetSiteBlacklist(bool value, const std::string& page_host);
+
   // Returns true if the webpage in the current original language should be
   // translated into the current target language automatically.
   bool ShouldAlwaysTranslate();
@@ -118,6 +133,17 @@ class TranslateUIDelegate {
   // translated into the current target language automatically.
   void SetAlwaysTranslate(bool value);
 
+  // Sets the value if the webpage in the |from_language| should be
+  // translated into the |to_language| automatically. Note that every
+  // |from_language| will only store the last |to_language| as the target.
+  void SetAlwaysTranslate(bool value,
+                          const std::string& from_language,
+                          const std::string& to_language);
+
+  // Returns the language to always translate |from_language| to, or empty
+  // string if none is found.

[Hiroshi Ichikawa, 2017/05/11 04:14:15]

s/if none is found/if it doesn't always translate |from_language|/ would be
clearer.

[jzw1, 2017/05/11 04:43:00]

I'll update the comment differently. 

+  std::string GetAlwaysTranslateToLanguage(const std::string& from_language);
+
   // Returns true if the Always Translate checkbox should be checked by default.
   bool ShouldAlwaysTranslateBeCheckedByDefault();