Introduce ActiveScriptController; track active extension scripts

extensions/common/permissions/permissions_data.h

Index: extensions/common/permissions/permissions_data.h
diff --git a/extensions/common/permissions/permissions_data.h b/extensions/common/permissions/permissions_data.h
index ee1715df6c97f0e091bba99af83ea4119da08675..f4f8bce4c223325294b9d0b7e28be05a01836d2e 100644
--- a/extensions/common/permissions/permissions_data.h
+++ b/extensions/common/permissions/permissions_data.h
@@ -177,6 +177,10 @@ class PermissionsData {
                                     int tab_id,
                                     std::string* error);
 
+  // Returns true if the user should be alerted that the |extension| is running
+  // a script.
+  static bool RequiresActionForScriptExecution(const Extension* extension);
+
   // Parse the permissions of a given extension in the initialization process.
   bool ParsePermissions(Extension* extension, base::string16* error);