Remove XP port from Blink LayoutTest related scripts.

third_party/WebKit/LayoutTests/SlowTests

Index: third_party/WebKit/LayoutTests/SlowTests
diff --git a/third_party/WebKit/LayoutTests/SlowTests b/third_party/WebKit/LayoutTests/SlowTests
index a09d05b71f41c0fb69626450148e6b0e60d93f83..67d96de26c8b9df7f55589098265c21a361eaaf9 100644
--- a/third_party/WebKit/LayoutTests/SlowTests
+++ b/third_party/WebKit/LayoutTests/SlowTests
@@ -72,12 +72,11 @@ crbug.com/451577 [ Debug ] fast/dom/gc-treescope.html  [ Slow ]
 crbug.com/451577 [ Debug ] fast/frames/calculate-round.html [ Slow ]
 crbug.com/451577 imported/web-platform-tests/IndexedDB/idbindex-multientry-big.htm [ Slow ]
 crbug.com/451577 [ Mac10.7 Mac10.8 ] inspector/elements/user-properties.html [ Slow ]
-crbug.com/451577 [ XP ] inspector/elements/user-properties.html [ Slow ]
-crbug.com/451577 [ Mac XP ] inspector/extensions/extensions-reload.html [ Slow ]
-crbug.com/451577 [ Mac XP ] inspector/extensions/extensions-resources.html [ Slow ]
-crbug.com/451577 [ Win10 XP ] inspector/extensions/extensions-sidebar.html [ Slow ]
-crbug.com/451577 [ Mac XP ] inspector/layers/layer-canvas-log.html [ Slow ]
-crbug.com/451577 [ Mac XP ] inspector/network/network-domain-filter.html [ Slow ]
+crbug.com/451577 [ Mac ] inspector/extensions/extensions-reload.html [ Slow ]
+crbug.com/451577 [ Mac ] inspector/extensions/extensions-resources.html [ Slow ]
+crbug.com/451577 [ Win10 ] inspector/extensions/extensions-sidebar.html [ Slow ]
+crbug.com/451577 [ Mac ] inspector/layers/layer-canvas-log.html [ Slow ]
+crbug.com/451577 [ Mac ] inspector/network/network-domain-filter.html [ Slow ]
 
 crbug.com/474121 editing/deleting/password-delete-performance.html [ Slow ]
 crbug.com/237245 [ Debug Win7 ] editing/selection/programmatic-selection-on-mac-is-directionless.html [ Slow ]