Revert of Add OpenGL context to Viewer.

tools/viewer/sk_app/win/VulkanWindowContext_win.h

Index: tools/viewer/sk_app/win/VulkanWindowContext_win.h
diff --git a/tools/viewer/sk_app/win/VulkanWindowContext_win.h b/tools/viewer/sk_app/win/VulkanWindowContext_win.h
new file mode 100644
index 0000000000000000000000000000000000000000..e0b5a156f99e27490009bb94129427f34af574aa
--- /dev/null
+++ b/tools/viewer/sk_app/win/VulkanWindowContext_win.h
@@ -0,0 +1,28 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef VULKANTESTCONTEXT_WIN_DEFINED
+#define VULKANTESTCONTEXT_WIN_DEFINED
+
+#ifdef SK_VULKAN
+
+#include <windows.h>
+#include "../VulkanWindowContext.h"
+
+namespace sk_app {
+
+// for Windows
+struct ContextPlatformData_win {
+    HINSTANCE fHInstance;
+    HWND      fHWnd;
+};
+
+}
+
+#endif // SK_VULKAN
+
+#endif