wptserve: Fix Python process leak on Windows.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py
index aaec90835b40b9aa7d27afefdb29b0f85b81ba18..ad1774fd68fda5979a9a5b5fa8342a88d99c9772 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/wptserve.py
@@ -60,7 +60,10 @@ class WPTServe(server_base.ServerBase):
             return
 
         # TODO(burnik): Figure out a cleaner way of stopping wptserve.
-        self._executive.interrupt(self._pid)
+        if self._platform.is_win():
+            self._executive.kill_process(self._pid)
+        else:
+            self._executive.interrupt(self._pid)
 
         # According to Popen.wait(), this can deadlock when using stdout=PIPE and/or stderr=PIPE.
         # We're using DEVNULL for both so that should not occur.