[Windows] Fix modal pages being laid out below soft buttons (#395)

Xamarin.Forms.Platform.WinRT.Phone/WindowsPhonePlatform.cs

@@ -14,18 +14,6 @@ namespace Xamarin.Forms.Platform.WinRT
 			_status.Hiding += OnStatusBarHiding;
 		}
 
-		internal override Rectangle WindowBounds
-		{
-			get
-			{
-				bool landscape = Device.Info.CurrentOrientation.IsLandscape ();
-				double offset = (landscape) ? _status.OccludedRect.Width : _status.OccludedRect.Height;
-
-				Rectangle original = base.WindowBounds;
-				return new Rectangle (original.X, original.Y, original.Width - ((landscape) ? offset : 0), original.Height - ((landscape) ? 0 : offset));
-			}
-		}
-
 		readonly StatusBar _status;
 
 		void OnStatusBarHiding (StatusBar sender, object args)

Xamarin.Forms.Platform.WinRT/Platform.cs

@@ -213,14 +213,14 @@ namespace Xamarin.Forms.Platform.WinRT
 			return new SizeRequest();
 		}
 
-		internal virtual Rectangle WindowBounds
+		internal virtual Rectangle ContainerBounds
 		{
 			get { return _bounds; }
 		}
 
 		internal void UpdatePageSizes()
 		{
-			Rectangle bounds = WindowBounds;
+			Rectangle bounds = ContainerBounds;
 			if (bounds.IsEmpty)
 				return;
 			foreach (Page root in _navModel.Roots)
@@ -435,27 +435,7 @@ namespace Xamarin.Forms.Platform.WinRT
 
 		void UpdateBounds()
 		{
-			_bounds = new Rectangle(0, 0, _page.ActualWidth, _page.ActualHeight);
-#if WINDOWS_UWP
-			StatusBar statusBar = MobileStatusBar;
-			if (statusBar != null)
-			{
-				bool landscape = Device.Info.CurrentOrientation.IsLandscape();
-				bool titleBar = CoreApplication.GetCurrentView().TitleBar.IsVisible;
-				double offset = landscape ? statusBar.OccludedRect.Width : statusBar.OccludedRect.Height;
-
-				_bounds = new Rectangle(0, 0, _page.ActualWidth - (landscape ? offset : 0), _page.ActualHeight - (landscape ? 0 : offset));
-
-				// Even if the MainPage is a ContentPage not inside of a NavigationPage, the calculated bounds
-				// assume the TitleBar is there even if it isn't visible. When UpdatePageSizes is called,
-				// _container.ActualWidth is correct because it's aware that the TitleBar isn't there, but the
-				// bounds aren't, and things can subsequently run under the StatusBar.
-				if (!titleBar)
-				{
-					_bounds.Width -= (_bounds.Width - _container.ActualWidth);
-				}
-			}
-#endif
+			_bounds = new Rectangle(0, 0, _container.ActualWidth, _container.ActualHeight);
 		}
 
 		void OnRendererSizeChanged(object sender, SizeChangedEventArgs sizeChangedEventArgs)
@@ -481,7 +461,7 @@ namespace Xamarin.Forms.Platform.WinRT
 					previousPage.Cleanup();
 			}
 
-			newPage.Layout(new Rectangle(0, 0, _page.ActualWidth, _page.ActualHeight));
+			newPage.Layout(ContainerBounds);
 
 			IVisualElementRenderer pageRenderer = newPage.GetOrCreateRenderer();
 			_container.Children.Add(pageRenderer.ContainerElement);
@@ -726,7 +706,7 @@ namespace Xamarin.Forms.Platform.WinRT
 
 			if (Device.Idiom == TargetIdiom.Phone)
 			{
-				double height = WindowBounds.Height;
+				double height = _page.ActualHeight;
 				stack.Height = height;
 				stack.Width = size.Width;
 				border.BorderThickness = new Windows.UI.Xaml.Thickness(0);