MythRenderOpenGL: Re-enable flushing

- this clearly causes presentation issues when the GPU cannot quite keep
up. Better to drop frames if necessary and highlight the performance
problem rather display video and overlays that are corrupted

mythtv/libs/libmythui/mythrender_opengl.cpp

@@ -191,7 +191,7 @@ MythRenderOpenGL::MythRenderOpenGL(const QSurfaceFormat& Format, QPaintDevice* D
     m_cachedMatrixUniforms(),
     m_cachedUniformLocations(),
     m_vao(0),
-    m_flushEnabled(false),
+    m_flushEnabled(true),
     m_openglDebugger(nullptr),
     m_openGLDebuggerFilter(QOpenGLDebugMessage::InvalidType),
     m_window(nullptr)
@@ -591,12 +591,6 @@ void MythRenderOpenGL::Release(void)
 #endif
 }
 
-void MythRenderOpenGL::MoveResizeWindow(const QRect &rect)
-{
-    if (m_window)
-        m_window->setGeometry(rect);
-}
-
 void MythRenderOpenGL::SetViewPort(const QRect &rect, bool viewportonly)
 {
     if (rect == m_viewport)

mythtv/libs/libmythui/mythrender_opengl.h

@@ -105,7 +105,6 @@ class MUI_PUBLIC MythRenderOpenGL : public QOpenGLContext, public QOpenGLFunctio
     int   GetExtraFeatures(void) const;
     QOpenGLFunctions::OpenGLFeatures GetFeatures(void) const;
     bool  IsRecommendedRenderer(void);
-    void  MoveResizeWindow(const QRect &rect);
     void  SetViewPort(const QRect &rect, bool viewportonly = false);
     QRect GetViewPort(void) { return m_viewport; }
     void  PushTransformation(const UIEffects &fx, QPointF &center);