Disable adaptive vsync option if unsupported

indra/newview/llfloaterhardwaresettings.cpp

@@ -150,9 +150,9 @@ BOOL LLFloaterHardwareSettings::postBuild()
 {
 	childSetAction("OK", onBtnOK, this);
 
-// Don't do this on Mac as their braindead GL versioning
-// sets this when 8x and 16x are indeed available
-//
+	// Don't do this on Mac as their braindead GL versioning
+	// sets this when 8x and 16x are indeed available
+	//
 #if !LL_DARWIN
 	if (gGLManager.mIsIntel || gGLManager.mGLVersion < 3.f)
 	{ //remove FSAA settings above "4x"
@@ -167,6 +167,12 @@ BOOL LLFloaterHardwareSettings::postBuild()
 	combo->remove(2);
 #endif
 
+	if (!gGLManager.mHasAdaptiveVSync)
+	{
+		LLComboBox* combo = getChild<LLComboBox>("vertical_sync");
+		combo->remove(2);
+	}
+
 	refresh();
 	center();