On windows, ignore WM_QUERYENDSESSION and close upon WM_ENDSESSION.

The messages can come through CFrame::MSWWindowProc and the wxApp implementation, so make sure to catch both.
Fixes issue 6546.

Source/Core/DolphinWX/Src/Frame.cpp

@@ -539,10 +539,25 @@ void CFrame::OnResize(wxSizeEvent& event)
 WXLRESULT CFrame::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
 {
 	if (WM_SYSCOMMAND == nMsg && (SC_SCREENSAVE == wParam || SC_MONITORPOWER == wParam))
+	{
 		return 0;
+	}
+	else if (nMsg == WM_QUERYENDSESSION)
+	{
+		// Indicate that the application will be able to close
+		return 1;
+	}
+	else if (nMsg == WM_ENDSESSION)
+	{
+		// Actually trigger the close now
+		Close(true);
+		return 0;
+	}
 	else
+	{
 		return wxFrame::MSWWindowProc(nMsg, wParam, lParam);
 	}
+}
 #endif
 
 void CFrame::OnHostMessage(wxCommandEvent& event)

Source/Core/DolphinWX/Src/Main.cpp

@@ -71,6 +71,8 @@ IMPLEMENT_APP(DolphinApp)
 
 BEGIN_EVENT_TABLE(DolphinApp, wxApp)
 	EVT_TIMER(wxID_ANY, DolphinApp::AfterInit)
+	EVT_QUERY_END_SESSION(DolphinApp::OnEndSession)
+	EVT_END_SESSION(DolphinApp::OnEndSession)
 END_EVENT_TABLE()
 
 #include <wx/stdpaths.h>
@@ -433,6 +435,15 @@ void DolphinApp::InitLanguageSupport()
 	}
 }
 
+void DolphinApp::OnEndSession(wxCloseEvent& event)
+{
+	// Close if we've recieved wxEVT_END_SESSION (ignore wxEVT_QUERY_END_SESSION)
+	if (!event.CanVeto())
+	{
+		main_frame->Close(true);
+	}
+}
+
 int DolphinApp::OnExit()
 {
 	WiimoteReal::Shutdown();

Source/Core/DolphinWX/Src/Main.h

@@ -33,6 +33,7 @@ private:
 	wxLocale *m_locale;
 
 	void AfterInit(wxTimerEvent& WXUNUSED(event));
+	void OnEndSession(wxCloseEvent& event);
 };
 
 DECLARE_APP(DolphinApp);