Enable Chrome to tweak search engines for some locales

components/search_engines/template_url_prepopulate_data.h

 // Copyright 2014 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 COMPONENTS_SEARCH_ENGINES_TEMPLATE_URL_PREPOPULATE_DATA_H_
 #define COMPONENTS_SEARCH_ENGINES_TEMPLATE_URL_PREPOPULATE_DATA_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 17 matching lines @@
 
 extern const int kMaxPrepopulatedEngineID;
 
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
 // Returns the current version of the prepopulate data, so callers can know when
 // they need to re-merge. If the prepopulate data comes from the preferences
 // file then it returns the version specified there.
 int GetDataVersion(PrefService* prefs);
 
-// Loads the set of TemplateURLs from the prepopulate data. On return,
+// Returns the prepopulated URLs for the current country.
 // |default_search_provider_index| is set to the index of the default search
-// provider.
+// provider within the returned vector.
 std::vector<std::unique_ptr<TemplateURLData>> GetPrepopulatedEngines(
     PrefService* prefs,
     size_t* default_search_provider_index);
 
+#if defined(OS_ANDROID)
+// Returns the prepopulated URLs associated with |locale|, if it differs from
+// the current country.  |locale| should be a two-character uppercase ISO 3166-1
+// country code.
+std::vector<std::unique_ptr<TemplateURLData>> GetLocalPrepopulatedEngines(

[Peter Kasting, 2016/09/21 21:45:08]

Nit: The only thing I worry about with this function name is that I don't know
whether it's sufficiently obvious that, if the locale is the same as the current
one, this returns an empty vector.  The function name kinda sounds like it just
gets the engines for a particular locale.

However, the comment does say this, and my suggested name was pretty awkward. 
So maybe this is good enough.  I don't know.

[Ian Wen, 2016/09/21 23:12:38]

I added a clarification to make it more clear that vector should be empty if
locale is already loaded.

+    const std::string& locale,
+    PrefService* prefs);
+#endif
+
 // Returns all prepopulated engines for all locales. Used only by tests.
 std::vector<const PrepopulatedEngine*> GetAllPrepopulatedEngines();
 
 // Returns a TemplateURLData for the specified prepopulated engine.
 std::unique_ptr<TemplateURLData> MakeTemplateURLDataFromPrepopulatedEngine(
     const PrepopulatedEngine& engine);
 
 // Removes prepopulated engines and their version stored in user prefs.
 void ClearPrepopulatedEnginesInPrefs(PrefService* prefs);
 
@@ skipping 12 matching lines @@
 // of search engines when user switches device region settings. For use on iOS
 // only.
 // TODO(ios): Once user can customize search engines ( http://crbug.com/153047 )
 // this declaration should be removed and the definition in the .cc file be
 // moved back to the anonymous namespace.
 int GetCurrentCountryID();
 
 }  // namespace TemplateURLPrepopulateData
 
 #endif  // COMPONENTS_SEARCH_ENGINES_TEMPLATE_URL_PREPOPULATE_DATA_H_