fix #resource tag in browser tests

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index d37bf2215f76f8c97423f85457d52a40d1c0e3eb..b839119b30fc9a6b63dc5a6b6125e743b0bb3e4d 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -418,7 +418,7 @@ class StandardTestSuite implements TestSuite {
     bool isLibraryDefinition = optionsFromFile['isLibraryDefinition'];
     if (!isLibraryDefinition && optionsFromFile['containsSourceOrImport']) {
       print('Warning for $filename: Browser tests require #library ' +
-            'in any file that uses #import or #source');
+            'in any file that uses #import, #source, or #resource');
     }
 
     final String component = configuration['component'];
@@ -743,7 +743,7 @@ class StandardTestSuite implements TestSuite {
     RegExp libraryDefinitionRegExp =
         const RegExp(@"^#library\(", multiLine: true);
     RegExp sourceOrImportRegExp =
-        const RegExp(@"^#(source|import)\(", multiLine: true);
+        const RegExp(@"^#(source|import|resource)\(", multiLine: true);
 
     // Read the entire file into a byte buffer and transform it to a
     // String. This will treat the file as ascii but the only parts