LOK: callbacks flush inline on every platform

0001 made the callback queue flush inline on macOS, where Aqua never
runs posted user events. Elsewhere scheduleFlush posted a user event,
so a callback reached the client only after the next turn of the
main loop. Ely's worker posts a command and waits for its result and
states inside the same request, which runs inside that loop (unipoll
on Linux, a window message on Windows): the result never came. The
queue now flushes inline everywhere; the flush event, its link and
stop() are gone.

diff --git a/desktop/source/lib/init.cxx b/desktop/source/lib/init.cxx
index 76a02127d..39b72fb1a 100644
--- a/desktop/source/lib/init.cxx
+++ b/desktop/source/lib/init.cxx
@@ -1609,7 +1609,6 @@ extern "C" {
 CallbackFlushHandler::CallbackFlushHandler(LibreOfficeKitDocument* pDocument, LibreOfficeKitCallback pCallback, void* pData)
     : m_pDocument(pDocument),
       m_pCallback(pCallback),
-      m_pFlushEvent(nullptr),
       m_pData(pData),
       m_nDisableCallbacks(0)
 {
@@ -1638,18 +1637,8 @@ CallbackFlushHandler::CallbackFlushHandler(LibreOfficeKitDocument* pDocument, Li
     }
 }
 
-void CallbackFlushHandler::stop()
-{
-    if (m_pFlushEvent)
-    {
-        Application::RemoveUserEvent(m_pFlushEvent);
-        m_pFlushEvent = nullptr;
-    }
-}
-
 CallbackFlushHandler::~CallbackFlushHandler()
 {
-    stop();
 }
 
 CallbackFlushHandler::queue_type2::iterator CallbackFlushHandler::toQueue2(CallbackFlushHandler::queue_type1::iterator pos)
@@ -2600,23 +2589,11 @@ void CallbackFlushHandler::invoke()
 
     m_queue1.clear();
     m_queue2.clear();
-    stop();
 }
 
 void CallbackFlushHandler::scheduleFlush()
 {
-#if defined(MACOSX)
-    // Aqua never runs posted user events: flush inline.
-    invoke();
-#else
-    if (!m_pFlushEvent)
-        m_pFlushEvent = Application::PostUserEvent(LINK(this, CallbackFlushHandler, FlushQueue));
-#endif
-}
-
-IMPL_LINK_NOARG(CallbackFlushHandler, FlushQueue, void*, void)
-{
-    m_pFlushEvent = nullptr;
+    // Ely's worker waits on callbacks inside a request: flush inline.
     invoke();
 }
 
diff --git a/desktop/inc/lib/init.hxx b/desktop/inc/lib/init.hxx
index 51d690307..6c21850fc 100644
--- a/desktop/inc/lib/init.hxx
+++ b/desktop/inc/lib/init.hxx
@@ -210,8 +210,6 @@ namespace desktop {
         void enqueueUpdatedTypes();
         void enqueueUpdatedType( int type, const SfxViewShell* sourceViewShell, int viewId );
 
-        void stop();
-
         /** we frequently want to scan the queue, and mostly when we do so, we only care about the element type
             so we split the queue in 2 to make the scanning cache friendly. */
         queue_type1 m_queue1;
@@ -246,12 +244,9 @@ namespace desktop {
         OString m_aViewRenderState;
         int m_viewId = -1; // view id of the associated SfxViewShell
         LibreOfficeKitCallback m_pCallback;
-        ImplSVEvent* m_pFlushEvent;
         void *m_pData;
         int m_nDisableCallbacks;
         std::recursive_mutex m_mutex;
-
-        DECL_LINK(FlushQueue, void*, void);
     };
 
     struct DESKTOP_DLLPUBLIC LibLODocument_Impl : public _LibreOfficeKitDocument