Revert "Delete HWC1"

This reverts commit 90f923493fa053655a203c34ea491086aeb07602.

Change-Id: If9da49e3bc85f8ff21ac1bd22a6bab97e9aa3103
diff --git a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
index 735e174..7c3f9b5 100644
--- a/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/GLES20RenderEngine.h
@@ -68,9 +68,15 @@
     virtual void setViewportAndProjection(size_t vpw, size_t vph,
             Rect sourceCrop, size_t hwh, bool yswap,
             Transform::orientation_flags rotation);
+#ifdef USE_HWC2
     virtual void setupLayerBlending(bool premultipliedAlpha, bool opaque,
             float alpha) override;
     virtual void setupDimLayerBlending(float alpha) override;
+#else
+    virtual void setupLayerBlending(bool premultipliedAlpha, bool opaque,
+            int alpha);
+    virtual void setupDimLayerBlending(int alpha);
+#endif
     virtual void setupLayerTexturing(const Texture& texture);
     virtual void setupLayerBlackedOut();
     virtual void setupFillWithColor(float r, float g, float b, float a);