Add test for multithreaded ActiveVerifier behavior.

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 0388e98a886cbe201c841195c4a83ddd87f28aed..528a3167661f785b953ee81e12c9579fb9d73c46 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -699,6 +699,9 @@
           ],
         }],
         ['OS == "win"', {
+          'dependencies': [
+            'scoped_handle_test_dll'
+          ],
           'sources!': [
             'file_descriptor_shuffle_unittest.cc',
             'files/dir_reader_posix_unittest.cc',
@@ -1677,6 +1680,17 @@
             },
           },
         },
+        {
+          'target_name': 'scoped_handle_test_dll',
+          'type': 'shared_library',
+          'dependencies': [
+            'base',
+          ],
+          'sources': [
+            'win/scoped_handle_test_dll.cc',
+            'win/scoped_handle_test_dll.h',
+          ],
+        },
       ],
     }],
     ['test_isolation_mode != "noop"', {