Draw border inside control bounds.

Added few more tests.

Perspex.Direct2D1.RenderTests/Controls/BorderTests.cs

@@ -36,5 +36,42 @@ namespace Perspex.Direct2D1.RenderTests.Controls
             this.RenderToFile(target);
             this.CompareImages();
         }
+
+        [TestMethod]
+        public void Border_2px_Border()
+        {
+            Decorator target = new Decorator
+            {
+                Padding = new Thickness(8),
+                Width = 200,
+                Height = 200,
+                Content = new Border
+                {
+                    BorderBrush = Brushes.Black,
+                    BorderThickness = 2,
+                }
+            };
+
+            this.RenderToFile(target);
+            this.CompareImages();
+        }
+
+        [TestMethod]
+        public void Border_Fill()
+        {
+            Decorator target = new Decorator
+            {
+                Padding = new Thickness(8),
+                Width = 200,
+                Height = 200,
+                Content = new Border
+                {
+                    Background = Brushes.Red,
+                }
+            };
+
+            this.RenderToFile(target);
+            this.CompareImages();
+        }
     }
 }

Perspex/Controls/Border.cs

@@ -27,15 +27,16 @@ namespace Perspex.Controls
                 Brush background = this.Background;
                 Brush borderBrush = this.BorderBrush;
                 double borderThickness = this.BorderThickness;
+                Rect rect = new Rect(this.Bounds.Size).Deflate(BorderThickness / 2);
 
                 if (background != null)
                 {
-                    context.FillRectange(background, new Rect(this.Bounds.Size));
+                    context.FillRectange(background, rect);
                 }
 
                 if (borderBrush != null && borderThickness > 0)
                 {
-                    context.DrawRectange(new Pen(borderBrush, borderThickness), new Rect(this.Bounds.Size));
+                    context.DrawRectange(new Pen(borderBrush, borderThickness), rect);
                 }
             }
         }

Perspex/Media/Brushes.cs

@@ -14,6 +14,7 @@ namespace Perspex.Media
         static Brushes()
         {
             Black = new SolidColorBrush(0xff000000);
+            Red = new SolidColorBrush(0xffff0000);
         }
 
         public static SolidColorBrush Black
@@ -21,5 +22,11 @@ namespace Perspex.Media
             get;
             private set;
         }
+
+        public static SolidColorBrush Red
+        {
+            get;
+            private set;
+        }
     }
 }

Perspex/Rect.cs

@@ -189,6 +189,17 @@ namespace Perspex
                    p.Y >= this.y && p.Y < this.y + this.height;
         }
 
+        /// <summary>
+        /// Deflates the rectangle.
+        /// </summary>
+        /// <param name="thickness">The thickness.</param>
+        /// <returns>The deflated rectangle.</returns>
+        /// <remarks>The deflated rectangle size cannot be less than 0.</remarks>
+        public Rect Deflate(double thickness)
+        {
+            return this.Deflate(new Thickness(thickness));
+        }
+
         /// <summary>
         /// Deflates the rectangle by a <see cref="Thickness"/>.
         /// </summary>