Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 50478)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 50479)
@@ -188,4 +188,12 @@
 {
     [pWindow setCollectionBehavior :NSWindowCollectionBehaviorFullScreenPrimary];
+}
+
+void darwinToggleFullscreenMode(NativeNSWindowRef pWindow)
+{
+    /* Toggle native fullscreen mode for passed pWindow.
+     * This method is available since 10.7 only. */
+    if ([pWindow respondsToSelector: @selector(toggleFullScreen:)])
+        [pWindow performSelector: @selector(toggleFullScreen:) withObject: (id)nil];
 }
 
Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp	(revision 50478)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.cpp	(revision 50479)
@@ -142,4 +142,9 @@
 {
     return ::darwinEnableFullscreenSupport(::darwinToNativeWindow(pWidget));
+}
+
+void darwinToggleFullscreenMode(QWidget *pWidget)
+{
+    return ::darwinToggleFullscreenMode(::darwinToNativeWindow(pWidget));
 }
 
Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 50478)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 50479)
@@ -80,4 +80,5 @@
 void darwinMinaturizeWindow(NativeNSWindowRef pWindow);
 void darwinEnableFullscreenSupport(NativeNSWindowRef pWindow);
+void darwinToggleFullscreenMode(NativeNSWindowRef pWindow);
 
 bool darwinOpenFile(NativeNSStringRef pstrFile);
@@ -242,4 +243,5 @@
 void darwinMinaturizeWindow(QWidget *pWidget);
 void darwinEnableFullscreenSupport(QWidget *pWidget);
+void darwinToggleFullscreenMode(QWidget *pWidget);
 bool darwinOpenFile(const QString &strFile);