Fix GN toolchains to use proper out dir.

components/variations.gypi

 # 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': [
     {
       # GN version: //components/variations
       'target_name': 'variations',
       'type': 'static_library',
@@ skipping 76 matching lines @@
           'type': 'none',
           'dependencies': [
             '../base/base.gyp:base',
           ],
           'variables': {
             'java_in_dir': 'variations/android/java',
           },
           'includes': [ '../build/java.gypi' ],
         },
         {
+          # GN version: //components/variations:variations_java
           'target_name': 'variations_jni_headers',
           'type': 'none',
           'sources': [
             'variations/android/java/src/org/chromium/components/variations/VariationsAssociatedData.java',
           ],
           'variables': {
             'jni_gen_package': 'variations',
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },
       ],
     }],
   ]
 }