Make sure the google wallet in-app payment support app is always installed.

chrome/common/extensions/extension.cc

 // Copyright (c) 2013 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.
 
 #include "chrome/common/extensions/extension.h"
 
 #include "base/base64.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 521 matching lines @@
   if (location() == Manifest::COMPONENT &&
       !CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kShowComponentExtensionOptions)) {
     return false;
   }
 
   // Always show unpacked extensions and apps.
   if (Manifest::IsUnpackedLocation(location()))
     return true;
 
+  // Don't show apps that aren't visible in either launcher or ntp.
+  if (is_app() && !ShouldDisplayInAppLauncher() && !ShouldDisplayInNewTabPage())
+    return false;
+
   // Unless they are unpacked, never show hosted apps. Note: We intentionally
   // show packaged apps and platform apps because there are some pieces of
   // functionality that are only available in chrome://extensions/ but which
   // are needed for packaged and platform apps. For example, inspecting
   // background pages. See http://crbug.com/116134.
   if (is_hosted_app())
     return false;
 
   return true;
 }
@@ skipping 687 matching lines @@
 
 UpdatedExtensionPermissionsInfo::UpdatedExtensionPermissionsInfo(
     const Extension* extension,
     const PermissionSet* permissions,
     Reason reason)
     : reason(reason),
       extension(extension),
       permissions(permissions) {}
 
 }   // namespace extensions