Remove remaining code related to pageLauncher

chrome/common/extensions/api/_api_features.json

 // 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.
 
 // See c/c/e/features/* to understand this file, in particular feature.h,
 // simple_feature.h, and base_feature_provider.h.
 
 {
   "activityLogPrivate": {
     "dependencies": ["permission:activityLogPrivate"],
@@ skipping 328 matching lines @@
     "contexts": ["blessed_extension"]
   },
   "pageActions": {
     "dependencies": ["manifest:page_actions"],
     "contexts": ["blessed_extension"]
   },
   "pageCapture": {
     "dependencies": ["permission:pageCapture"],
     "contexts": ["blessed_extension"]
   },
-  "pageLauncher": {
-    "dependencies": ["manifest:page_launcher"],
-    "contexts": ["blessed_extension"]
-  },
   "permissions": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app", "platform_app"],
     "contexts": "all",
     "matches": ["<all_urls>"]
   },
   "power": {
     "dependencies": ["permission:power"],
     "contexts": ["blessed_extension"]
   },
@@ skipping 207 matching lines @@
   },
   "webview": {
     "dependencies": ["permission:webview"],
     "contexts": ["blessed_extension"]
   },
   "windows": {
     "dependencies": ["permission:tabs"],
     "contexts": ["blessed_extension"]
   }
 }