generated_api.h should have its body generated into generated_api.cc

chrome/common/extensions/api/api.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'api',
       'type': 'static_library',
       'sources': [
@@ skipping 59 matching lines @@
           'tabs.json',
           'usb.idl',
           'webview.json',
           'web_navigation.json',
           'web_request.json',
           'windows.json',
         ],
         'cc_dir': 'chrome/common/extensions/api',
         'root_namespace': 'extensions::api',
       },
+      'dependencies': [
+        '<(DEPTH)/skia/skia.gyp:skia',
+        '<(DEPTH)/sync/sync.gyp:sync',
+      ],
       'conditions': [
         ['OS=="android"', {
           'schema_files!': [
             'usb.idl',
           ],
         }],
         ['OS!="chromeos"', {
           'schema_files!': [
             'file_browser_handler_internal.json',
             'rtc_private.idl',
           ],
         }],
       ],
     },
   ],
 }