First pass at VulkanViewer

tools/vulkan/VulkanViewer.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 VulkanViewer_DEFINED
+#define VulkanViewer_DEFINED
+
+#include "Application.h"
+#include "Window.h"
+
+class SkCanvas;
+
+class VulkanViewer : public Application {
+public:
+    VulkanViewer(int argc, char** argv, void* platformData);
+    ~VulkanViewer() override;
+
+    bool onKey(int key, bool keyDown);
+    bool onMouse(int x, int y, bool mouseDown);
+    void onPaint(SkCanvas* canvas);
+
+    void onIdle(float dt) override;
+
+private:
+    Window* fWindow;
+};
+
+
+#endif