[Typed CSSOM] Get computed values for custom properties

third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html

Index: third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html
diff --git a/third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html b/third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html
index 504b5318f992280d17333294d852ea1ce08ff00d..4f159d4518035b7e098c7ab84c64b6d8d47fc622 100644
--- a/third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html
+++ b/third_party/WebKit/LayoutTests/typedcssom/computedstyle/computedStylePropertyMap.html
@@ -34,6 +34,10 @@ test(function() {
 }, 'Unsupported and unserializable property returns null.');
 
 test(function() {
+  assert_throws(null, function() { computedStyleMap.get('bananas'); });
+}, 'get() throws for an invalid property.');
+
+test(function() {
   assert_false(computedStyleMap.has('max-zoom'));
 }, 'has() return false for an unsupported property.');