Revert of Make extensions DSE persistent in browser prefs

components/search_engines/default_search_manager.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_DEFAULT_SEARCH_MANAGER_H_
 #define COMPONENTS_SEARCH_ENGINES_DEFAULT_SEARCH_MANAGER_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 81 matching lines @@
   // that Default Search is explicitly disabled. |source|, if not NULL, will be
   // filled in with the source of the result.
   TemplateURLData* GetDefaultSearchEngine(Source* source) const;
 
   // Gets the source of the current Default Search Engine value.
   Source GetDefaultSearchEngineSource() const;
 
   // Write default search provider data to |pref_service_|.
   void SetUserSelectedDefaultSearchEngine(const TemplateURLData& data);
 
+  // Override the default search provider with an extension.
+  void SetExtensionControlledDefaultSearchEngine(const TemplateURLData& data);
+
+  // Clear the extension-provided default search engine. Does not explicitly
+  // disable Default Search. The new current default search engine will be
+  // defined by policy, extensions, or pre-populated data.
+  void ClearExtensionControlledDefaultSearchEngine();
+
   // Clear the user's default search provider choice from |pref_service_|. Does
   // not explicitly disable Default Search. The new default search
   // engine will be defined by policy, extensions, or pre-populated data.
   void ClearUserSelectedDefaultSearchEngine();
 
  private:
   // Handles changes to kDefaultSearchProviderData pref. This includes sync and
   // policy changes. Calls LoadDefaultSearchEngineFromPrefs() and
   // NotifyObserver() if the effective DSE might have changed.
   void OnDefaultSearchPrefChanged();
@@ skipping 38 matching lines @@
   // prefs). This will be null if no value was set in the pref store.
   std::unique_ptr<TemplateURLData> prefs_default_search_;
 
   // True if the default search is currently enforced by policy.
   bool default_search_controlled_by_policy_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultSearchManager);
 };
 
 #endif  // COMPONENTS_SEARCH_ENGINES_DEFAULT_SEARCH_MANAGER_H_