Add performance overlay for DXVA2 renderer

app/streaming/video/overlaymanager.cpp

@@ -0,0 +1,25 @@
+#include "overlaymanager.h"
+
+OverlayManager::OverlayManager()
+{
+    memset(m_Overlays, 0, sizeof(m_Overlays));
+}
+
+bool OverlayManager::isOverlayEnabled(OverlayManager::OverlayType type)
+{
+    return m_Overlays[type].enabled;
+}
+
+char* OverlayManager::getOverlayText(OverlayType type)
+{
+    return m_Overlays[type].text;
+}
+
+void OverlayManager::setOverlayState(OverlayManager::OverlayType type, bool enabled)
+{
+    m_Overlays[type].enabled = enabled;
+    if (!enabled) {
+        // Set the text to empty string on disable
+        m_Overlays[type].text[0] = 0;
+    }
+}