SF: RenderEngine->drawLayers takes GraphicBuffer instead of ANativeWindow

RE interface is going to be moved to AIDL. In order to make it AIDL
compatible, drawLayer needs to take sp<GraphicBuffer> (because it's
already flattenable) instead of ANativeWindow.

Bug: 150064821
Test: atest CompositionEngineTest
Test: adb shell /data/nativetest64/.../libsurfaceflinger_unittest
Test: atest RenderEngineTest
Change-Id: Ifef487c93753d03f949f00e055a66ac6f0a98cb0
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 3a4f349..557feaf 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -314,9 +314,10 @@
 
     auto onMessageReceived(int32_t what) { return mFlinger->onMessageReceived(what); }
 
-    auto captureScreenImplLocked(
-            const RenderArea& renderArea, SurfaceFlinger::TraverseLayersFunction traverseLayers,
-            ANativeWindowBuffer* buffer, bool useIdentityTransform, bool forSystem, int* outSyncFd) {
+    auto captureScreenImplLocked(const RenderArea& renderArea,
+                                 SurfaceFlinger::TraverseLayersFunction traverseLayers,
+                                 const sp<GraphicBuffer>& buffer, bool useIdentityTransform,
+                                 bool forSystem, int* outSyncFd) {
         bool ignored;
         return mFlinger->captureScreenImplLocked(renderArea, traverseLayers, buffer,
                                                  useIdentityTransform, forSystem, outSyncFd,