Makes construction of (ash)RemoteWindowTreeHostWin explicit

ash/shell_init_params.cc

Index: ash/shell_init_params.cc
diff --git a/ash/shell_init_params.cc b/ash/shell_init_params.cc
new file mode 100644
index 0000000000000000000000000000000000000000..87e5be8bd41be78e84f91f6754a29c70e194fa4b
--- /dev/null
+++ b/ash/shell_init_params.cc
@@ -0,0 +1,19 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/shell_init_params.h"
+
+#include "ash/shell_delegate.h"
+
+namespace ash {
+
+#if defined(OS_WIN)
+ShellInitParams::ShellInitParams() : delegate(NULL), remote_hwnd(NULL) {}
+#else
+ShellInitParams::ShellInitParams() : delegate(NULL) {}
+#endif
+
+ShellInitParams::~ShellInitParams() {}
+
+}  // namespace ash