Revert "Remove gl surfaces from DisplayDevice."

This reverts commit ce0ad96d3c23b6b7bc4d6a540141ea1111b4430e.

Reason for revert: breaks screenrecord (b/119534075)

Change-Id: I45af7b49a490601fcc68ca55c79f590bb0db1b01
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index dc42414..c5b60f1 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -473,6 +473,11 @@
             return *this;
         }
 
+        auto& setRenderSurface(std::unique_ptr<renderengine::Surface> renderSurface) {
+            mCreationArgs.renderSurface = std::move(renderSurface);
+            return *this;
+        }
+
         auto& setSecure(bool secure) {
             mCreationArgs.isSecure = secure;
             return *this;