Rename VulkanViewer to Viewer, take 2.

tools/vulkan/viewer/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"
-#include "gm.h"
-#include "SkAnimTimer.h"
-#include "Slide.h"
-
-class SkCanvas;
-
-class VulkanViewer : public Application {
-public:
-    VulkanViewer(int argc, char** argv, void* platformData);
-    ~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;
-
-};
-
-
-#endif