SF: Move DisplaySurface into CompositionEngine

The CompositionEngine now provides the interface for a DisplaySurface.

For the moment SurfaceFlinger still provides implementations, but those
may be moved into CompositionEngine too.

Test: atest libsurfaceflinger_unittest libcompositionengine_test
Bug: 121291683
Change-Id: I446e57952d59abc137b3b23203b2e093f6262ef3
diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index 3862d8b..64db6ef 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -36,6 +36,7 @@
     srcs: [
         "src/CompositionEngine.cpp",
         "src/Display.cpp",
+        "src/DisplaySurface.cpp",
         "src/DumpHelpers.cpp",
         "src/Output.cpp",
         "src/OutputCompositionState.cpp",
@@ -50,6 +51,7 @@
     srcs: [
         "mock/CompositionEngine.cpp",
         "mock/Display.cpp",
+        "mock/DisplaySurface.cpp",
         "mock/Output.cpp",
     ],
     static_libs: [