More cleanup in the Vulkan viewer

tools/vulkan/Window.h

Index: tools/vulkan/Window.h
diff --git a/tools/vulkan/Window.h b/tools/vulkan/Window.h
index f7b4f132ad8a1952ab3218cec0dbf518087f3d11..c8971eebbe11d29eae78e7a5721ebe1972c06a95 100644
--- a/tools/vulkan/Window.h
+++ b/tools/vulkan/Window.h
@@ -21,6 +21,7 @@ public:
 
     virtual void setTitle(const char*) = 0;
     virtual void show() = 0;
+    virtual void inval() = 0;
 
     struct AttachmentInfo {
         int fSampleCount;
@@ -122,9 +123,15 @@ public:
     void onPaint();
     void onResize(uint32_t width, uint32_t height);
 
+    uint32_t width() { return fWidth; }
+    uint32_t height() { return fHeight;  }
+
 protected:
     Window();
 
+    uint32_t     fWidth;
+    uint32_t     fHeight;
+
     OnCharFunc   fCharFunc;
     void*        fCharUserData;
     OnKeyFunc    fKeyFunc;