[iOS] Default BarTextColor/BarBackgroundColor will no longer override values set in custom renderers (#233)beta-2.3.1-pre1

* [Controls] Improve TabbedPage test case

iOS should default to the color used in a custom renderer instead of to
the global default color.

* [iOS] TabbedPage Bar*Color default is better

Will use the color set by a custom renderer, if any, instead of always
pulling from global appearance.

1 files changed, 10 insertions, 5 deletions

diff --git a/Xamarin.Forms.Controls/CoreGallery.cs b/Xamarin.Forms.Controls/CoreGallery.cs
index bf4fe399..8fd1f7bc 100644
--- a/Xamarin.Forms.Controls/CoreGallery.cs
+++ b/Xamarin.Forms.Controls/CoreGallery.cs
@@ -96,12 +96,17 @@ namespace Xamarin.Forms.Controls
 		{
 			AutomationId = "TabbedPageRoot";
 
-			BarBackgroundColor = Color.Maroon;
-			BarTextColor = Color.Yellow;
 
-			Device.StartTimer(TimeSpan.FromSeconds(2), () => {
-				BarBackgroundColor = Color.Default;
-				BarTextColor = Color.Default;
+			Device.StartTimer(TimeSpan.FromSeconds(6), () => {
+				BarBackgroundColor = Color.Maroon;
+				BarTextColor = Color.Yellow;
+
+				Device.StartTimer(TimeSpan.FromSeconds(6), () => {
+					BarBackgroundColor = Color.Default;
+					BarTextColor = Color.Default;
+
+					return false;
+				});
 
 				return false;
 			});