Handle "frame-less" creation of Touch objects.

LayoutTests/fast/events/touch/script-tests/document-create-touch.js

Index: LayoutTests/fast/events/touch/script-tests/document-create-touch.js
diff --git a/LayoutTests/fast/events/touch/script-tests/document-create-touch.js b/LayoutTests/fast/events/touch/script-tests/document-create-touch.js
index bf2986e31c14f2d13a460a1eda645d96569bc410..071b21217bf2098cce33443f64827f064323c154 100644
--- a/LayoutTests/fast/events/touch/script-tests/document-create-touch.js
+++ b/LayoutTests/fast/events/touch/script-tests/document-create-touch.js
@@ -57,4 +57,22 @@ shouldBe("badParamsTouch.webkitRadiusX", "0");
 shouldBe("badParamsTouch.webkitRadiusY", "0");
 shouldBeNaN("badParamsTouch.webkitRotationAngle");
 shouldBeNaN("badParamsTouch.webkitForce");
+
+// Should not crash when invoked on a detached Document.
+var detachedTouch;
+shouldBeNonNull("detachedTouch = document.implementation.createDocument('a', 'b').createTouch()");
+shouldBeNull("detachedTouch.target");
+shouldBe("detachedTouch.identifier", "0");
+shouldBe("detachedTouch.pageX", "0");
+shouldBe("detachedTouch.pageY", "0");
+shouldBe("detachedTouch.screenX", "0");
+shouldBe("detachedTouch.screenY", "0");
+shouldBe("detachedTouch.radiusX", "0");
+shouldBe("detachedTouch.radiusY", "0");
+shouldBeNaN("detachedTouch.force");
+shouldBe("detachedTouch.webkitRadiusX", "0");
+shouldBe("detachedTouch.webkitRadiusY", "0");
+shouldBeNaN("detachedTouch.webkitRotationAngle");
+shouldBeNaN("detachedTouch.webkitForce");
+
 isSuccessfullyParsed();