enhance: fore invalidate measure after data context of BisectStateIndicator changed

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Models/Bisect.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 
 namespace SourceGit.Models
 {
@@ -9,6 +10,7 @@ public enum BisectState
         Detecting,
     }
 
+    [Flags]
     public enum BisectCommitFlag
     {
         None = 0,

src/Views/BisectStateIndicator.cs

@@ -65,6 +65,12 @@ public override void Render(DrawingContext context)
                 RenderImpl(context, Brushes.Red, _bad, x);
         }
 
+        protected override void OnDataContextChanged(EventArgs e)
+        {
+            base.OnDataContextChanged(e);
+            InvalidateMeasure();
+        }
+
         protected override Size MeasureOverride(Size availableSize)
         {
             var desiredFlags = Models.BisectCommitFlag.None;