Add Client Attribute to FetchEvent- Blink Side.

LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js

Index: LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js
diff --git a/LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js b/LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js
index cacf87bb68eabb2990ed4f06e54da554d67a18cd..15848f63dcb38dd0d9ecd8c4cfe55eaa2f99fcd8 100644
--- a/LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js
+++ b/LayoutTests/http/tests/serviceworker/resources/interfaces-worker.js
@@ -82,7 +82,7 @@ test(function() {
       true, 'Default FetchEvent.cancelable should be true');
     assert_equals(
       new FetchEvent('FetchEvent').bubbles,
-      false, 'Default FetchEvent.bubbles should be true');
+      false, 'Default FetchEvent.bubbles should be false');
     assert_equals(
       new FetchEvent('FetchEvent').isReload,
       false, 'Default FetchEvent.isReload should be false');
@@ -99,4 +99,8 @@ test(function() {
       new FetchEvent('FetchEvent', {request : req, isReload : true}).request.url,
       'http://localhost/',
       'FetchEvent.request.url should return the value it was initialized to');
+    assert_equals(
+      new FetchEvent('FetchEvent').client,
+      null,
+      'FetchEvent.client should return null if it was not initialized');
   }, 'Event constructors');