Switch SurfaceFlinger to HWC 2.0

Enables SurfaceFlinger to speak to version 2.0 of the Hardware Composer
HAL instead of version 1.x (also removing support for the framebuffer
HAL). By default, however, this functionality is disabled. In order to
enable it, USE_HWC2 must be set to true in Android.mk.

Change-Id: I4589e02ac2165236b10ff2f7cb772f87e0d3daab
diff --git a/services/surfaceflinger/RenderEngine/GLES10RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES10RenderEngine.h
index f9c7c04..61abd6a 100644
--- a/services/surfaceflinger/RenderEngine/GLES10RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES10RenderEngine.h
@@ -30,7 +30,12 @@
 class GLES10RenderEngine : public GLES11RenderEngine {
     virtual ~GLES10RenderEngine();
 protected:
+#ifdef USE_HWC2
+    virtual void setupLayerBlending(bool premultipliedAlpha, bool opaque,
+            float alpha) override;
+#else
     virtual void setupLayerBlending(bool premultipliedAlpha, bool opaque, int alpha);
+#endif
 };
 
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