Cleanup: Remove an unused member variable.

chrome/browser/content_settings/host_content_settings_map.h

Index: chrome/browser/content_settings/host_content_settings_map.h
diff --git a/chrome/browser/content_settings/host_content_settings_map.h b/chrome/browser/content_settings/host_content_settings_map.h
index 65ba51bd0b171c79cfb7890d05da7983866d85ec..9819c3ac711a9b5abb4f2f5d0c71a32180f1ef8a 100644
--- a/chrome/browser/content_settings/host_content_settings_map.h
+++ b/chrome/browser/content_settings/host_content_settings_map.h
@@ -217,10 +217,6 @@ class HostContentSettingsMap
   // Whether this settings map is for an OTR session.
   bool is_off_the_record_;
 
-  // Whether we are currently updating preferences, this is used to ignore
-  // notifications from the preferences service that we triggered ourself.
-  bool updating_preferences_;
-
   // Content setting providers.
   ProviderMap content_settings_providers_;