VulkanViewer on Android
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1903253003

Review URL: https://codereview.chromium.org/1903253003
diff --git a/tools/vulkan/viewer/Slide.h b/tools/vulkan/viewer/Slide.h
index f75e3fd..cdc225b 100644
--- a/tools/vulkan/viewer/Slide.h
+++ b/tools/vulkan/viewer/Slide.h
@@ -9,6 +9,7 @@
 #define Slide_DEFINED
 
 #include "SkRefCnt.h"
+#include "SkSize.h"
 #include "SkString.h"
 
 class SkCanvas;
@@ -18,6 +19,8 @@
 public:
     virtual ~Slide() {}
 
+    virtual SkISize getDimensions() const = 0;
+
     virtual void draw(SkCanvas* canvas) = 0;
     virtual bool animate(const SkAnimTimer&) { return false;  }
     virtual void load() {}