Detach the dependency from host_content_settings_map to extension.

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index c239bebeb08f4466ac7a0bfde7697bc33df6b31b..55954a68136b1c950cd892b24621991d29d5a9c5 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -33,6 +33,7 @@
 
 class ExtensionSyncService;
 class GURL;
+class HostContentSettingsMap;
 class Profile;
 
 namespace base {
@@ -365,6 +366,10 @@ class ExtensionService
   // notification is desired the calling code is responsible for doing that.
   void TerminateExtension(const std::string& extension_id);
 
+  // Register self and content settings API with the specified map.
+  void RegisterContentSettings(
+      HostContentSettingsMap* host_content_settings_map);
+
   // Adds/Removes update observers.
   void AddUpdateObserver(extensions::UpdateObserver* observer);
   void RemoveUpdateObserver(extensions::UpdateObserver* observer);