Small fix that makes overal UI (including dragging spliiters) much, much faster.

Flushing messages meant that for every event, UI was reaccomodating everything. This is relly slow.
Messages will have to happen sometime later, during iteration most likely.
I still can't fix the overall code editor slowness on Mesa+Radeon, I suspect it's a driver issue.

scene/main/scene_tree.cpp

@@ -392,86 +392,11 @@ void SceneTree::input_event(const Ref<InputEvent> &p_event) {
 
 	Ref<InputEvent> ev = p_event;
 	ev->set_id(++last_id); //this should work better
-#if 0
-	switch(ev.type) {
-
-		case InputEvent::MOUSE_BUTTON: {
-
-			Matrix32 ai = root->get_final_transform().affine_inverse();
-			Vector2 g = ai.xform(Vector2(ev.mouse_button.global_x,ev.mouse_button.global_y));
-			Vector2 l = ai.xform(Vector2(ev->get_pos().x,ev->get_pos().y));
-			ev->get_pos().x=l.x;
-			ev->get_pos().y=l.y;
-			ev.mouse_button.global_x=g.x;
-			ev.mouse_button.global_y=g.y;
-
-		} break;
-		case InputEvent::MOUSE_MOTION: {
-
-			Matrix32 ai = root->get_final_transform().affine_inverse();
-			Vector2 g = ai.xform(Vector2(ev.mouse_motion.global_x,ev.mouse_motion.global_y));
-			Vector2 l = ai.xform(Vector2(ev.mouse_motion.x,ev.mouse_motion.y));
-			Vector2 r = ai.xform(Vector2(ev->get_relative().x,ev->get_relative().y));
-			ev.mouse_motion.x=l.x;
-			ev.mouse_motion.y=l.y;
-			ev.mouse_motion.global_x=g.x;
-			ev.mouse_motion.global_y=g.y;
-			ev->get_relative().x=r.x;
-			ev->get_relative().y=r.y;
-
-		} break;
-		case InputEvent::SCREEN_TOUCH: {
-
-			Matrix32 ai = root->get_final_transform().affine_inverse();
-			Vector2 t = ai.xform(Vector2(ev.screen_touch.x,ev.screen_touch.y));
-			ev.screen_touch.x=t.x;
-			ev.screen_touch.y=t.y;
-
-		} break;
-		case InputEvent::SCREEN_DRAG: {
-
-			Matrix32 ai = root->get_final_transform().affine_inverse();
-			Vector2 t = ai.xform(Vector2(ev.screen_drag.x,ev.screen_drag.y));
-			Vector2 r = ai.xform(Vector2(ev.screen_drag.relative_x,ev.screen_drag.relative_y));
-			Vector2 s = ai.xform(Vector2(ev.screen_drag.speed_x,ev.screen_drag.speed_y));
-			ev.screen_drag.x=t.x;
-			ev.screen_drag.y=t.y;
-			ev.screen_drag.relative_x=r.x;
-			ev.screen_drag.relative_y=r.y;
-			ev.screen_drag.speed_x=s.x;
-			ev.screen_drag.speed_y=s.y;
-		} break;
-	}
-
-#endif
 
 	MainLoop::input_event(ev);
-#if 0
-	_call_input_pause("input","_input",ev);
-
-	call_group(GROUP_CALL_REVERSE|GROUP_CALL_REALTIME|GROUP_CALL_MULIILEVEL,"_gui_input","_gui_input",p_event); //special one for GUI, as controls use their own process check
-
-	//call_group(GROUP_CALL_REVERSE|GROUP_CALL_REALTIME|GROUP_CALL_MULIILEVEL,"input","_input",ev);
-
-	/*
-	if (ev.type==InputEvent::KEY && ev->is_pressed() && !ev->is_echo() && ev->get_scancode()==KEY_F12) {
-
-		print_line("RAM: "+itos(Memory::get_static_mem_usage()));
-		print_line("DRAM: "+itos(Memory::get_dynamic_mem_usage()));
-	}
-	if (ev.type==InputEvent::KEY && ev->is_pressed() && !ev->is_echo() && ev->get_scancode()==KEY_F11) {
-
-		Memory::dump_static_mem_to_file("memdump.txt");
-	}
-	*/
-
-	//transform for the rest
-#else
 
 	call_group_flags(GROUP_CALL_REALTIME, "_viewports", "_vp_input", ev); //special one for GUI, as controls use their own process check
 
-#endif
-
 	if (ScriptDebugger::get_singleton() && ScriptDebugger::get_singleton()->is_remote()) {
 		//quit from game window using F8
 		Ref<InputEventKey> k = ev;
@@ -482,7 +407,7 @@ void SceneTree::input_event(const Ref<InputEvent> &p_event) {
 
 	_flush_ugc();
 	root_lock--;
-	MessageQueue::get_singleton()->flush(); //small little hack
+	//MessageQueue::get_singleton()->flush(); //flushing here causes UI and other places slowness
 
 	root_lock++;
 
@@ -503,7 +428,7 @@ void SceneTree::input_event(const Ref<InputEvent> &p_event) {
 		input_handled = true;
 		_flush_ugc();
 		root_lock--;
-		MessageQueue::get_singleton()->flush(); //small little hack
+		//MessageQueue::get_singleton()->flush(); //flushing here causes UI and other places slowness
 	} else {
 		input_handled = true;
 		root_lock--;