Have the Debugger extension api check that it has access to the tab

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 a23fb2b56d173897cf5f71858cbbdde8b887d6e3..9470d586ba8320bfbe1bdddbaf3febbc27f81755 100644
--- a/extensions/common/permissions/permissions_data.h
+++ b/extensions/common/permissions/permissions_data.h
@@ -68,6 +68,14 @@ class PermissionsData {
   // whitelist of extensions that can script all pages.
   static bool CanExecuteScriptEverywhere(const Extension* extension);
 
+  // Returns true if the given |url| is restricted for the given |extension|,
+  // as is commonly the case for chrome:// urls.
+  // NOTE: You probably want to use CanAccessPage().
+  static bool IsRestrictedUrl(const GURL& document_url,
+                              const GURL& top_frame_url,
+                              const Extension* extension,
+                              std::string* error);
+
   // Sets the runtime permissions of the given |extension| to |permissions|.
   void SetActivePermissions(const PermissionSet* active) const;