Stub out not yet implemented controller methods, so we don't have to wait for timeouts but fail imm…

content/shell/layout_test_controller_host.h

Index: content/shell/layout_test_controller_host.h
diff --git a/content/shell/layout_test_controller_host.h b/content/shell/layout_test_controller_host.h
index e31f61084b12f0b036b72222400d0470781388e3..7e63badcb13ef15fc793b4dc8e231b2fa9bff8dd 100644
--- a/content/shell/layout_test_controller_host.h
+++ b/content/shell/layout_test_controller_host.h
@@ -51,6 +51,9 @@ class LayoutTestControllerHost : public RenderViewHostObserver {
   void OnSetShouldStayOnPageAfterHandlingBeforeUnload(bool should_stay_on_page);
   void OnWaitUntilDone();
 
+  void OnNotImplemented(const std::string& object_name,
+                        const std::string& method_name);
+
   static std::map<RenderViewHost*, LayoutTestControllerHost*> controllers_;
   static std::string expected_pixel_hash_;