fdo#49914, rulers: DarkShadow color is supposed to be dark (even on Mac).

Change-Id: I09d0c5d6797b6df9e84ad3574fc420241fe72707
diff --git a/vcl/aqua/source/window/salframe.cxx b/vcl/aqua/source/window/salframe.cxx
index f2e77e5..456bb91 100644
--- a/vcl/aqua/source/window/salframe.cxx
+++ b/vcl/aqua/source/window/salframe.cxx
@@ -1262,7 +1262,6 @@ void AquaSalFrame::UpdateSettings( AllSettings& rSettings )
    aStyleSettings.SetDialogColor( aBackgroundColor );
    aStyleSettings.SetLightBorderColor( aBackgroundColor );
    Color aShadowColor( aStyleSettings.GetShadowColor() );
    aStyleSettings.SetDarkShadowColor( aShadowColor );
    aShadowColor.IncreaseLuminance( 32 );
    aStyleSettings.SetShadowColor( aShadowColor );

diff --git a/vcl/ios/source/window/salframe.cxx b/vcl/ios/source/window/salframe.cxx
index ef0e680..c86aa7d 100644
--- a/vcl/ios/source/window/salframe.cxx
+++ b/vcl/ios/source/window/salframe.cxx
@@ -735,7 +735,6 @@ void IosSalFrame::UpdateSettings( AllSettings& rSettings )
    aStyleSettings.SetDialogColor( aBackgroundColor );
    aStyleSettings.SetLightBorderColor( aBackgroundColor );
    Color aShadowColor( aStyleSettings.GetShadowColor() );
    aStyleSettings.SetDarkShadowColor( aShadowColor );
    aShadowColor.IncreaseLuminance( 32 );
    aStyleSettings.SetShadowColor( aShadowColor );