Check the format of an applicationServerKey when used to register a push subscription.

third_party/WebKit/LayoutTests/http/tests/push_messaging/resources/push-constants.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// NIST P-256 public key made available to tests. Must be an uncompressed
+// point in accordance with SEC1 2.3.3.
+const PUBLIC_KEY = [
+    0x04, 0x56, 0x23, 0xC0, 0x45, 0xD7, 0x6C, 0x5D, 0x45, 0x1A, 0x29,
+    0x19, 0xAA, 0xE5, 0x02, 0x2F, 0x43, 0x55, 0xC2, 0x5C, 0x59, 0x86,
+    0x69, 0xA0, 0xAD, 0xD7, 0x2D, 0x54, 0x22, 0xD8, 0x43, 0xB6, 0xCD,
+    0xE3, 0x33, 0xB4, 0xBB, 0x66, 0x2F, 0x47, 0xE5, 0xE6, 0x20, 0xFF,
+    0x0E, 0x10, 0x7F, 0xCD, 0xA3, 0x44, 0x8C, 0x65, 0x54, 0x64, 0x7E,
+    0x25, 0xF3, 0x67, 0xF4, 0x7C, 0x4B, 0x0C, 0xBD, 0xCF, 0xF4
+];