test-hwc2: Added virtual Display tests

VirtualDisplay tests added.
Test: Ran on (heavily modified) ryu
Change-Id: I5cc92d11d4cde6c3407d71652f87ea3c3fb63228
diff --git a/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.h b/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.h
index c2029ab..cb811e0 100644
--- a/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.h
+++ b/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.h
@@ -243,6 +243,7 @@
     static const std::array<bool, 6> mCompositionSupport;
 };
 
+class Hwc2TestVirtualBuffer;
 
 class Hwc2TestDisplayDimension : public Hwc2TestProperty<UnsignedArea> {
 public:
@@ -250,12 +251,12 @@
 
     std::string dump() const;
 
-    void setDependent(Hwc2TestBuffer* buffer);
+    void setDependent(Hwc2TestVirtualBuffer* buffer);
 
 private:
     void updateDependents();
 
-    Hwc2TestBuffer* mBuffer;
+    std::set<Hwc2TestVirtualBuffer*> mBuffers;
 
     static const std::vector<UnsignedArea> mDefaultDisplayDimensions;
     static const std::vector<UnsignedArea> mBasicDisplayDimensions;