WIN use Reschedule instead of own dispatch loops

Since we're filtering the wakeup timer event in the main dispatch
loop, we should use Application::Reschedule in the Backend.

Change-Id: Ie02c3533e8a6a7905281f129489e4f6f53f74692

vcl/win/app/salinst.cxx

@@ -732,6 +732,7 @@ LRESULT CALLBACK SalComWndProc( HWND, UINT nMsg, WPARAM wParam, LPARAM lParam, i
             while ( PeekMessageW(&aMsg, nullptr, SAL_MSG_TIMER_CALLBACK,
                                  SAL_MSG_TIMER_CALLBACK, PM_REMOVE) )
                 assert( "Multiple timer messages in queue" );
+            assert( 0 == wParam );
             if ( 0 == wParam )
                 EmitTimerCallback();
             break;

vcl/win/gdi/salprn.cxx

@@ -1288,24 +1288,12 @@ BOOL CALLBACK SalPrintAbortProc( HDC hPrnDC, int /* nError */ )
 {
     SalData*    pSalData = GetSalData();
     WinSalPrinter* pPrinter;
-    bool        bWhile = TRUE;
-    int         i = 0;
+    bool        bWhile = true;
 
     do
     {
         // process messages
-        MSG aMsg;
-        if ( PeekMessageW( &aMsg, nullptr, 0, 0, PM_REMOVE ) )
-        {
-            TranslateMessage( &aMsg );
-            DispatchMessageW( &aMsg );
-
-            i++;
-            if ( i > 15 )
-                bWhile = FALSE;
-        }
-        else
-            bWhile = FALSE;
+        bWhile = Application::Reschedule( true );
 
         pPrinter = pSalData->mpFirstPrinter;
         while ( pPrinter )
@@ -1468,25 +1456,7 @@ bool WinSalPrinter::StartJob( const OUString* pFileName,
 
     // As the Telecom Balloon Fax driver tends to send messages repeatedly
     // we try to process first all, and then insert a dummy message
-    bool bWhile = TRUE;
-    int  i = 0;
-    do
-    {
-        // process messages
-        MSG aMsg;
-        if ( PeekMessageW( &aMsg, nullptr, 0, 0, PM_REMOVE ) )
-        {
-            TranslateMessage( &aMsg );
-            DispatchMessageW( &aMsg );
-
-            i++;
-            if ( i > 15 )
-                bWhile = FALSE;
-        }
-        else
-            bWhile = FALSE;
-    }
-    while ( bWhile );
+    while ( Application::Reschedule( true ) );
     BOOL const ret = PostMessageW(GetSalData()->mpFirstInstance->mhComWnd, SAL_MSG_DUMMY, 0, 0);
     SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
 

vcl/win/window/salframe.cxx

@@ -5705,14 +5705,7 @@ LRESULT CALLBACK SalFrameWndProc( HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lP
                 // messages in the message queue and dispatch them before we return control to the system.
 
                 if ( nRet )
-                {
-                    MSG msg;
-
-                    while( PeekMessage( &msg, nullptr, 0, 0, PM_REMOVE ) )
-                    {
-                        DispatchMessage( &msg );
-                    }
-                }
+                    while ( Application::Reschedule( true ) );
             }
             else
             {