Extract ScopedTestNSSDB from nss_util.

chrome/chrome_browser.gypi

 # Copyright 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.
 
 {
   'variables': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 1817 matching lines @@
       'browser/plugins/plugin_installer.h',
       'browser/plugins/plugin_installer_observer.cc',
       'browser/plugins/plugin_installer_observer.h',
       'browser/plugins/plugins_resource_service.cc',
       'browser/plugins/plugins_resource_service.h',
     ],
     'chrome_browser_nss_sources': [
       'browser/certificate_manager_model.cc',
       'browser/certificate_manager_model.h',
       'browser/net/nss_context.cc',
+      'browser/net/nss_context.h',
       'browser/net/nss_context_chromeos.cc',
-      'browser/net/nss_context.h',
       'browser/net/nss_context_linux.cc',
       'third_party/mozilla_security_manager/nsNSSCertHelper.cpp',
       'third_party/mozilla_security_manager/nsNSSCertHelper.h',
       'third_party/mozilla_security_manager/nsNSSCertificate.cpp',
       'third_party/mozilla_security_manager/nsNSSCertificate.h',
       'third_party/mozilla_security_manager/nsUsageArrayHelper.cpp',
       'third_party/mozilla_security_manager/nsUsageArrayHelper.h',
     ],
     # Used on all platforms when notifications are enabled.
     'chrome_browser_notifications_sources': [
@@ skipping 1377 matching lines @@
             'app/chrome_breakpad_client.cc',
             'app/chrome_breakpad_client.h',
           ],
           'dependencies': [
             '../components/components.gyp:breakpad_component',
             '../components/components.gyp:breakpad_host',
           ],
         }],
         ['use_nss==1', {
           'sources': [ '<@(chrome_browser_nss_sources)' ],
+          'conditions': [
+            ['chromeos==1', {
+               'sources!': [ 'browser/net/nss_context_linux.cc' ],
+              }, { # chromeos==0
+               'sources!': [ 'browser/net/nss_context_chromeos.cc' ],
+              }],
+          ],
         }],
         ['notifications==1', {
           'sources': [ '<@(chrome_browser_notifications_sources)' ],
           'conditions': [
             ['OS!="android"', {
               'sources': [
                 '<@(chrome_browser_non_android_notifications_sources)',
               ],
             }],
           ],
@@ skipping 368 matching lines @@
             'package_name': 'org/chromium/chrome/browser',
             'template_deps': ['browser/android/tab_load_status.h'],
           },
           'includes': [ '../build/android/java_cpp_template.gypi' ],
         },
       ],
      },
     ],
   ],
 }