SW backend for viewer on Windows

tools/viewer/sk_app/win/WindowContextFactory_win.h

 
 /*
  * 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 WindowContextFactory_win_DEFINED
 #define WindowContextFactory_win_DEFINED
 
 #include <Windows.h>
 
 namespace sk_app {
 
 class WindowContext;
 struct DisplayParams;
 
 namespace window_context_factory {
 
 WindowContext* NewVulkanForWin(HWND, const DisplayParams&);
 
 WindowContext* NewGLForWin(HWND, const DisplayParams&);
 
+WindowContext* NewRasterForWin(HWND, const DisplayParams&);
+
 }  // namespace window_context_factory
 
 }  // namespace sk_app
 
 #endif