More cleanup in the Vulkan viewer

tools/vulkan/viewer/VulkanViewer.h

Index: tools/vulkan/viewer/VulkanViewer.h
diff --git a/tools/vulkan/viewer/VulkanViewer.h b/tools/vulkan/viewer/VulkanViewer.h
index 649cb22a5387f0b3c887896c60d9fc721c65a5f8..7e39f88a768aab5231ac47a6f16b90046f122d32 100644
--- a/tools/vulkan/viewer/VulkanViewer.h
+++ b/tools/vulkan/viewer/VulkanViewer.h
@@ -11,6 +11,7 @@
 #include "../Application.h"
 #include "../Window.h"
 #include "gm.h"
+#include "SkAnimTimer.h"
 #include "Slide.h"
 
 class SkCanvas;
@@ -21,23 +22,38 @@ public:
     ~VulkanViewer() override;
 
     bool onKey(Window::Key key, Window::InputState state, uint32_t modifiers);
+    bool onChar(SkUnichar, uint32_t modifiers);
     void onPaint(SkCanvas* canvas);
-
     void onIdle(double ms) override;
 
 private:
     void initSlides();
+    void setupCurrentSlide(int previousSlide);
 
     void drawStats(SkCanvas* canvas);
 
+    void changeZoomLevel(float delta);
+    void updateMatrix();
+
     Window*      fWindow;
 
     static const int kMeasurementCount = 64;  // should be power of 2 for fast mod
     double fMeasurements[kMeasurementCount];
     int fCurrentMeasurement;
 
+    SkAnimTimer            fAnimTimer;
     SkTArray<sk_sp<Slide>> fSlides;
     int                    fCurrentSlide;
+
+    bool                   fDisplayStats;
+
+    // transform data
+    SkMatrix               fLocalMatrix;
+    SkScalar               fZoomCenterX;
+    SkScalar               fZoomCenterY;
+    SkScalar               fZoomLevel;
+    SkScalar               fZoomScale;
+
 };