Change the platform app manifest structure.

chrome/common/extensions/extension_manifest_constants.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_EXTENSION_MANIFEST_CONSTANTS_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_MANIFEST_CONSTANTS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 75 matching lines @@
   extern const char kPageAction[];
   extern const char kPageActionDefaultIcon[];
   extern const char kPageActionDefaultPopup[];
   extern const char kPageActionDefaultTitle[];
   extern const char kPageActionIcons[];
   extern const char kPageActionId[];
   extern const char kPageActionPopup[];
   extern const char kPageActionPopupPath[];
   extern const char kPageActions[];
   extern const char kPermissions[];
-  extern const char kPlatformApp[];
+  extern const char kPlatformAppBackground[];
+  extern const char kPlatformAppBackgroundPage[];
+  extern const char kPlatformAppBackgroundScripts[];
   extern const char kPlugins[];
   extern const char kPluginsPath[];
   extern const char kPluginsPublic[];
   extern const char kPublicKey[];
   extern const char kRequirements[];
   extern const char kRunAt[];
   extern const char kSandboxedPages[];
   extern const char kSandboxedPagesCSP[];
   extern const char kShiftKey[];
   extern const char kShortcutKey[];
@@ skipping 211 matching lines @@
   extern const char kPlatformAppNeedsManifestVersion2[];
   extern const char kOneUISurfaceOnly[];
   extern const char kReservedMessageFound[];
   extern const char kWebRequestConflictsWithLazyBackground[];
 #if defined(OS_CHROMEOS)
   extern const char kIllegalPlugins[];
 #endif
 }  // namespace extension_manifest_errors
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_MANIFEST_CONSTANTS_H_