fetch: Drop Headers from HeadersInit typedef declaration.

content/browser/service_worker/service_worker_browsertest.cc

Index: content/browser/service_worker/service_worker_browsertest.cc
diff --git a/content/browser/service_worker/service_worker_browsertest.cc b/content/browser/service_worker/service_worker_browsertest.cc
index 531f5bde7db3f7f512ba88769a105406cadff476..2c7cf80401d0724986c186d9175f77f93a3a136e 100644
--- a/content/browser/service_worker/service_worker_browsertest.cc
+++ b/content/browser/service_worker/service_worker_browsertest.cc
@@ -1230,8 +1230,8 @@ IN_PROC_BROWSER_TEST_F(ServiceWorkerVersionBrowserTest, FetchEvent_Response) {
   EXPECT_EQ(301, response.status_code);
   EXPECT_EQ("Moved Permanently", response.status_text);
   ServiceWorkerHeaderMap expected_headers;
-  expected_headers["Content-Language"] = "fi";
-  expected_headers["Content-Type"] = "text/html; charset=UTF-8";
+  expected_headers["content-language"] = "fi";
+  expected_headers["content-type"] = "text/html; charset=UTF-8";
   EXPECT_EQ(expected_headers, response.headers);
 
   std::string body;