Explicitly delete node_modules directory after running tests on Windows

tools/run_tests/post_test_node.bat

@@ -0,0 +1,30 @@
+@rem Copyright 2016, Google Inc.
+@rem All rights reserved.
+@rem
+@rem Redistribution and use in source and binary forms, with or without
+@rem modification, are permitted provided that the following conditions are
+@rem met:
+@rem
+@rem     * Redistributions of source code must retain the above copyright
+@rem notice, this list of conditions and the following disclaimer.
+@rem     * Redistributions in binary form must reproduce the above
+@rem copyright notice, this list of conditions and the following disclaimer
+@rem in the documentation and/or other materials provided with the
+@rem distribution.
+@rem     * Neither the name of Google Inc. nor the names of its
+@rem contributors may be used to endorse or promote products derived from
+@rem this software without specific prior written permission.
+@rem
+@rem THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+@rem "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+@rem LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+@rem A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+@rem OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+@rem SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+@rem LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+@rem DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+@rem THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+@rem (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+@rem OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+rmdir node_modules /S /Q

tools/run_tests/run_tests.py

@@ -290,7 +290,10 @@ class NodeLanguage(object):
       return [['tools/run_tests/build_node.sh', self.node_version]]
 
   def post_tests_steps(self):
-    return []
+    if self.platform == 'windows':
+      return [['tools\\run_tests\\post_test_node.bat']]
+    else:
+      return []
 
   def makefile_name(self):
     return 'Makefile'