ActivateTopScissor doesn't belong in UIContext::Begin.

UI/EmuScreen.cpp

@@ -1165,11 +1165,6 @@ void EmuScreen::preRender() {
 	using namespace Draw;
 	DrawContext *draw = screenManager()->getDrawContext();
 	draw->BeginFrame();
-	// Let's be consistent for the entire frame.  We skip the UI texture if we don't need it.
-	hasVisibleUI_ = hasVisibleUI();
-	if (hasVisibleUI_) {
-		screenManager()->getUIContext()->BeginFrame();
-	}
 	// Here we do NOT bind the backbuffer or clear the screen, unless non-buffered.
 	// The emuscreen is different than the others - we really want to allow the game to render to framebuffers
 	// before we ever bind the backbuffer for rendering. On mobile GPUs, switching back and forth between render
@@ -1268,7 +1263,8 @@ void EmuScreen::render() {
 	if (invalid_)
 		return;
 
-	if (hasVisibleUI_) {
+	if (hasVisibleUI()) {
+		screenManager()->getUIContext()->BeginFrame();
 		renderUI();
 	}