Make BeforeInstallPromptEvent cancelable

third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html

Index: third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html
diff --git a/third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html b/third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html
index f8763d2f686f135e411d1d8882854455692fba46..1f993adfe884edeac5e77c5f7dfedd362f8dcf2f 100644
--- a/third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html
+++ b/third_party/WebKit/LayoutTests/app_banner/before-install-prompt-event-constructor.html
@@ -5,9 +5,14 @@
 
 test(function() {
     assert_false(new BeforeInstallPromptEvent('eventType').bubbles, 'bubbles');
-    assert_true(new BeforeInstallPromptEvent('eventType').cancelable, 'cancelable');
+    assert_false(new BeforeInstallPromptEvent('eventType').cancelable, 'cancelable');
 }, 'No initializer passed');
 
+test(function() {
+    assert_true(new BeforeInstallPromptEvent('eventType', { bubbles: true } ).bubbles, 'bubbles');
+    assert_true(new BeforeInstallPromptEvent('eventType', { cancelable: true } ).cancelable, 'cancelable');
+}, 'Initializer values not respected');
+
 test(function() {
     var event = new BeforeInstallPromptEvent('eventType', { platforms: ['a'] });
     assert_array_equals(['a'], event.platforms, 'platforms');