Make sk_app::WindowContext directly create a SkSurface without an intermediate GrRenderTarget

tools/viewer/sk_app/WindowContext.h

Index: tools/viewer/sk_app/WindowContext.h
diff --git a/tools/viewer/sk_app/WindowContext.h b/tools/viewer/sk_app/WindowContext.h
index 2c526a4bfe0d176c35536e221021e6f39ada9d2b..917eb4edf81b086d84971911a73efcd4af748eea 100644
--- a/tools/viewer/sk_app/WindowContext.h
+++ b/tools/viewer/sk_app/WindowContext.h
@@ -45,13 +45,14 @@ public:
     GrContext* getGrContext() const { return fContext; }
 
     sk_sp<SkSurface> createOffscreenSurface(bool sRGB);
-    sk_sp<SkSurface> createRenderSurface(sk_sp<GrRenderTarget>, int colorBits);
     void presentRenderSurface(sk_sp<SkSurface> renderSurface, sk_sp<GrRenderTarget> rt,
                               int colorBits);
 
 protected:
     virtual bool isGpuContext() { return true;  }
 
+    sk_sp<SkSurface> createRenderSurface(GrBackendRenderTargetDesc, int colorBits);

[Brian Osman, 2016/07/19 16:08:18]

Pass the desc by const& in both places? (Why is it passed by value here, and by
pointer later?)

[bsalomon, 2016/07/19 16:19:17]

It's required for this function and optional for the other (there is no desc
when createSurface is called from createOffscreenSurface).

+
     GrContext*        fContext;
 
     int               fWidth;
@@ -62,7 +63,7 @@ protected:
 
 private:
     sk_sp<SkSurface> createSurface(
-            sk_sp<GrRenderTarget>, int colorBits, bool offscreen, bool forceSRGB);
+            GrBackendRenderTargetDesc*, int colorBits, bool offscreen, bool forceSRGB);
 };
 
 }   // namespace sk_app