Revert "Revert "Add ExternalTexture class into RenderEngine inte..."

Revert submission 14199598-revert-14086921-renderengine-external-tex-QJNBWQMQEU

Reason for revert: Prepare for relanding
Reverted Changes:
I01e65a7f4:Revert "Update WaylandRenderSurface to accomodate ...
I7d58118c1:Revert "Update Readback VTS to align with RenderEn...
I1501890f4:Revert "Add ExternalTexture class into RenderEngin...

Added the following fixes:
1. CachedSet renders to intermediate texture variable rather than
mTexture directly, since mTexture is not guaranteed to be nonnull.
2. Add null check when setting new buffer in BLAST.

Bug: 185524947
Bug: 180767535
Test: builds, boots
Test: librenderengine_test
Change-Id: I52ea82e24336b496d996bbe3e445db0affe1abb8
diff --git a/libs/renderengine/threaded/RenderEngineThreaded.h b/libs/renderengine/threaded/RenderEngineThreaded.h
index 61ae9b8..eb6098e 100644
--- a/libs/renderengine/threaded/RenderEngineThreaded.h
+++ b/libs/renderengine/threaded/RenderEngineThreaded.h
@@ -48,8 +48,6 @@
 
     void genTextures(size_t count, uint32_t* names) override;
     void deleteTextures(size_t count, uint32_t const* names) override;
-    void cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) override;
-    void unbindExternalTextureBuffer(uint64_t bufferId) override;
     size_t getMaxTextureSize() const override;
     size_t getMaxViewportDims() const override;
 
@@ -60,14 +58,19 @@
 
     status_t drawLayers(const DisplaySettings& display,
                         const std::vector<const LayerSettings*>& layers,
-                        const sp<GraphicBuffer>& buffer, const bool useFramebufferCache,
-                        base::unique_fd&& bufferFence, base::unique_fd* drawFence) override;
+                        const std::shared_ptr<ExternalTexture>& buffer,
+                        const bool useFramebufferCache, base::unique_fd&& bufferFence,
+                        base::unique_fd* drawFence) override;
 
     void cleanFramebufferCache() override;
     int getContextPriority() override;
     bool supportsBackgroundBlur() override;
     void onPrimaryDisplaySizeChanged(ui::Size size) override;
 
+protected:
+    void mapExternalTextureBuffer(const sp<GraphicBuffer>& buffer, bool isRenderable) override;
+    void unmapExternalTextureBuffer(const sp<GraphicBuffer>& buffer) override;
+
 private:
     void threadMain(CreateInstanceFactory factory);
     void waitUntilInitialized() const;