Make extensions DSE persistent in browser prefs (Reland)

components/search_engines/template_url.h

Index: components/search_engines/template_url.h
diff --git a/components/search_engines/template_url.h b/components/search_engines/template_url.h
index d57aed22627266467d0f47eb6bf5b413c5bbface..7e33d95f8f86b28e4da51d44ceefa9e16b9e1d17 100644
--- a/components/search_engines/template_url.h
+++ b/components/search_engines/template_url.h
@@ -489,10 +489,6 @@ class TemplateURL {
 
     // Whether the search engine is supposed to be default.
     bool wants_to_be_default_engine;
-
-    // Used to resolve conflicts when there are multiple extensions specifying
-    // the default search engine. The most recently-installed wins.
-    base::Time install_time;
   };
 
   explicit TemplateURL(const TemplateURLData& data, Type type = NORMAL);
@@ -512,6 +508,12 @@ class TemplateURL {
                           const TemplateURLData* data,
                           const SearchTermsData& search_terms_data);
 
+  // Special case for search_terms_replacement_key comparison, because of
+  // its special initialization in TemplateURL constructor.
+  static bool SearchTermsReplacementKeysMatch(
+      const std::string& search_terms_replacement_key1,
+      const std::string& search_terms_replacement_key2);
+
   const TemplateURLData& data() const { return data_; }
 
   const base::string16& short_name() const { return data_.short_name(); }
@@ -594,6 +596,10 @@ class TemplateURL {
     extension_info_ = std::move(extension_info);
   }
 
+  const AssociatedExtensionInfo* GetExtensionInfoForTesting() const {
+    return extension_info_.get();
+  }
+
   // Returns true if |url| supports replacement.
   bool SupportsReplacement(const SearchTermsData& search_terms_data) const;