Dispatch texture destruction off of render thread for screenshots

This is only enabled when the skia threaded variant renderengine is
enabled. This essentially defers texture deletion until after
drawLayers() is invoked, which shaves off time from the main SF thread.

Bug: 179959621
Bug: 180767535
Test: perfetto trace
Change-Id: I333091d8792fdd0dc01076c73af2956da9ee73df
diff --git a/libs/renderengine/skia/SkiaRenderEngine.h b/libs/renderengine/skia/SkiaRenderEngine.h
index 12b8586..79a1040 100644
--- a/libs/renderengine/skia/SkiaRenderEngine.h
+++ b/libs/renderengine/skia/SkiaRenderEngine.h
@@ -36,6 +36,7 @@
 class SkiaRenderEngine : public RenderEngine {
 public:
     static std::unique_ptr<SkiaRenderEngine> create(const RenderEngineCreationArgs& args);
+    SkiaRenderEngine(RenderEngineType type) : RenderEngine(type) {}
     ~SkiaRenderEngine() override {}
 
     virtual void primeCache() const override{};