Shotdown browser cooperatively with taskill on win platform.

tools/telemetry/telemetry/core/platform/win_platform_backend.py

Index: tools/telemetry/telemetry/core/platform/win_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/platform/win_platform_backend.py b/tools/telemetry/telemetry/core/platform/win_platform_backend.py
index de9ec475741195492fa9b9b1674a84f39e95f404..9cadc8c2371814b19053dded9458aa0b1ffb38db 100644
--- a/tools/telemetry/telemetry/core/platform/win_platform_backend.py
+++ b/tools/telemetry/telemetry/core/platform/win_platform_backend.py
@@ -39,6 +39,7 @@ except ImportError:
   shellcon = None
   win32api = None
   win32con = None
+  win32gui = None
   win32process = None
   win32security = None
 
@@ -362,3 +363,9 @@ class WinPlatformBackend(desktop_platform_backend.DesktopPlatformBackend):
     finally:
       sock.close()
     return struct.unpack('Q', response)[0] >> start & ((1 << length) - 1)
+
+  def IsCooperativeShutdownSupported(self):
+    return True
+
+  def CooperativelyShutdown(self, proc):
+    subprocess.call(['taskkill', '/F', '/T', '/PID', str(proc.pid)])

[Ken Russell (switch to Gerrit), 2014/11/14 18:51:38]

This is far from a cooperative shutdown; it forcibly kills the process tree. The
approach in https://codereview.chromium.org/726563003 is much closer to the how
the browser shuts down on users' machines. I am continuing to refine that patch.

Further, this approach will mask any real bugs in the browser causing
sub-processes to leak.