Add some layout tests about behavior on undefined and null.

LayoutTests/fast/canvas/drawImage-with-broken-image.html

Index: LayoutTests/fast/canvas/drawImage-with-broken-image.html
diff --git a/LayoutTests/fast/canvas/drawImage-with-broken-image.html b/LayoutTests/fast/canvas/drawImage-with-broken-image.html
index 3a9462cc50cde37a780a213782b1c30e160042be..afb0f143f003c867e1a913439a8851b31a6082d7 100644
--- a/LayoutTests/fast/canvas/drawImage-with-broken-image.html
+++ b/LayoutTests/fast/canvas/drawImage-with-broken-image.html
@@ -14,10 +14,13 @@
 
     var ctx = document.createElement("canvas").getContext('2d');
     function draw() {
-        // null images should throw TypeError
+        // null and undefined images should throw TypeError
         shouldThrow("ctx.drawImage(null, 0, 0)");
         shouldThrow("ctx.drawImage(null, 0, 0, 20, 20)");
         shouldThrow("ctx.drawImage(null, 0, 0, 20, 20, 0, 0, 20, 20)");
+        shouldThrow("ctx.drawImage(undefined, 0, 0)");
+        shouldThrow("ctx.drawImage(undefined, 0, 0, 20, 20)");
+        shouldThrow("ctx.drawImage(undefined, 0, 0, 20, 20, 0, 0, 20, 20)");
 
         // broken images should not throw
         shouldThrow("ctx.drawImage(invalidImage, 0, 0)");