Add slides to VulkanViewer

tools/vulkan/viewer/SKPSlide.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 SKPSlide_DEFINED
+#define SKPSlide_DEFINED
+
+#include "Slide.h"
+#include "SkPicture.h"
+
+class SKPSlide : public Slide {
+public:
+    SKPSlide(const char* name, sk_sp<const SkPicture> pic);
+    ~SKPSlide() override;
+
+    void draw(SkCanvas* canvas) override;
+    SkString getName() override { return fName; }
+
+private:
+    sk_sp<const SkPicture> fPic;
+    SkIRect                fCullRect;
+    SkString               fName;
+};
+
+#endif