Select search engine based on locale

- Allow user specific overrides of search engine based on locale.
- If user does not have an override for search engine
  use default locale specific search engine.

CR-Fixed:910238

Change-Id: I8775ce669c1625992954b53ec5ed39503f304596
diff --git a/src/com/android/browser/PreferenceKeys.java b/src/com/android/browser/PreferenceKeys.java
index 15ec6a0..ce6c4cb 100644
--- a/src/com/android/browser/PreferenceKeys.java
+++ b/src/com/android/browser/PreferenceKeys.java
@@ -145,4 +145,8 @@
     static final String PREF_LEGAL_PRIVACY_POLICY = "legal_privacy_policy";
 
     static final String ACTION_RELOAD_PAGE = "reload";
+
+    // User preference
+    static final String PREF_USER_SEARCH_ENGINE = "user_search_engine-";
+
 }