Add --headless flag to Windows

headless/lib/headless_devtools_client_browsertest.cc

Index: headless/lib/headless_devtools_client_browsertest.cc
diff --git a/headless/lib/headless_devtools_client_browsertest.cc b/headless/lib/headless_devtools_client_browsertest.cc
index 7c58943e32b477facfe031185c6486c78f7f7f2f..5796e0fd45a9381851ead8a220f2fceee287a03d 100644
--- a/headless/lib/headless_devtools_client_browsertest.cc
+++ b/headless/lib/headless_devtools_client_browsertest.cc
@@ -717,7 +717,11 @@ class HeadlessCrashObserverTest : public HeadlessAsyncDevTooledBrowserTest,
   // Make sure we don't fail because the renderer crashed!
   void RenderProcessExited(base::TerminationStatus status,
                            int exit_code) override {
+#if defined(OS_WIN)
+    EXPECT_EQ(base::TERMINATION_STATUS_PROCESS_CRASHED, status);
+#else
     EXPECT_EQ(base::TERMINATION_STATUS_ABNORMAL_TERMINATION, status);
+#endif
   }
 };