Don't allow updating tabs to javascript URLs without host

chrome/browser/extensions/extension_function.h

Index: chrome/browser/extensions/extension_function.h
diff --git a/chrome/browser/extensions/extension_function.h b/chrome/browser/extensions/extension_function.h
index 02bab68335e1a1e332ae53ebaa965959dc6f1e45..d763696231c78a61685b1f7198df3a3e163f8d45 100644
--- a/chrome/browser/extensions/extension_function.h
+++ b/chrome/browser/extensions/extension_function.h
@@ -66,6 +66,15 @@ class ExtensionFunction : public base::RefCounted<ExtensionFunction> {
   virtual void Run() = 0;
 
  protected:
+  // Gets the extension that called this function. This can return NULL for
+  // async functions.
+  Extension* GetExtension() {
+    if (dispatcher())
+      return dispatcher()->GetExtension();
+    else
+      return NULL;
+  }
+
   // The peer to the dispatcher that will service this extension function call.
   scoped_refptr<ExtensionFunctionDispatcher::Peer> peer_;