Add get_drt.py to test.dart, so that testing browser components updates DumpRenderTree.

tools/testing/dart/test_options.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library("test_options_parser");
 
 #import("dart:io");
+#import("drt_updater.dart");
 
 List<String> defaultTestSelectors =
     const ['dartc', 'samples', 'standalone', 'corelib', 'co19', 'language',
            'isolate', 'vm', 'client', 'dartdoc', 'utils'];
 
 /**
  * Specification of a single test option.
  *
  * The name of the specification is used as the key for the option in
  * the Map returned from the [TestOptionParser] parse method.
@@ skipping 431 matching lines @@
     // Expand components.
     var components = configuration['component'];
     if (components.contains(',')) {
       var result = new List<Map>();
       for (var component in components.split(',')) {
         var newConfiguration = new Map.from(configuration);
         newConfiguration['component'] = component;
         result.addAll(_expandConfigurations(newConfiguration));
       }
       return result;
+    } else {
+      // All components eventually go through this path, after expansion.
+      if (DumpRenderTreeUpdater.componentRequiresDRT(components)) {
+        DumpRenderTreeUpdater.update();
+      }
     }
 
     // Adjust default timeout based on mode and component.
     if (configuration['timeout'] == -1) {
       var timeout = 60;
       switch (configuration['component']) {
         case 'dartc':
         case 'chromium':
         case 'dartium':
         case 'frogium':
@@ skipping 67 matching lines @@
         return option;
       }
     }
     print('Unknown test option $name');
     exit(1);
   }
 
 
   List<_TestOptionSpecification> _options;
 }