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/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index 27d3dc5..1c2853a 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -38,12 +38,16 @@
 #define VDS_LOGV(msg, ...) ALOGV("[%s] " msg, \
         mDisplayName.c_str(), ##__VA_ARGS__)
 
-static const char* dbgCompositionTypeStr(DisplaySurface::CompositionType type) {
+static const char* dbgCompositionTypeStr(compositionengine::DisplaySurface::CompositionType type) {
     switch (type) {
-        case DisplaySurface::COMPOSITION_UNKNOWN: return "UNKNOWN";
-        case DisplaySurface::COMPOSITION_GLES:    return "GLES";
-        case DisplaySurface::COMPOSITION_HWC:     return "HWC";
-        case DisplaySurface::COMPOSITION_MIXED:   return "MIXED";
+        case compositionengine::DisplaySurface::COMPOSITION_UNKNOWN:
+            return "UNKNOWN";
+        case compositionengine::DisplaySurface::COMPOSITION_GLES:
+            return "GLES";
+        case compositionengine::DisplaySurface::COMPOSITION_HWC:
+            return "HWC";
+        case compositionengine::DisplaySurface::COMPOSITION_MIXED:
+            return "MIXED";
         default:                                  return "<INVALID>";
     }
 }