Add a global on/off switch for content settings and expose a toggle on the Website Settings options…

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 952196c852baa4f52b7461197edd62fd50697564..5642c0f431020ecb01689beb7a7bd58e0c0b5faa 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -990,6 +990,10 @@ const char kUseCustomChromeFrame[] = "browser.custom_chrome_frame";
 // Dictionary of content settings applied to all hosts by default.
 const char kDefaultContentSettings[] = "profile.default_content_settings";
 
+// Dictionary of content settings that can globally disallow all hosts by
+// default.
+const char kOverrideContentSettings[] = "profile.override_content_settings";
+
 // Boolean indicating whether the clear on exit pref was migrated to content
 // settings yet.
 const char kContentSettingsClearOnExitMigrated[] =