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.cpp b/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.cpp
index b5522de..5b3bbeb 100644
--- a/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.cpp
+++ b/services/surfaceflinger/tests/hwc2/Hwc2TestProperties.cpp
@@ -335,9 +335,9 @@
     return dmp.str();
 }
 
-void Hwc2TestDisplayDimension::setDependent(Hwc2TestBuffer* buffer)
+void Hwc2TestDisplayDimension::setDependent(Hwc2TestVirtualBuffer* buffer)
 {
-    mBuffer = buffer;
+    mBuffers.insert(buffer);
     updateDependents();
 }
 
@@ -345,8 +345,8 @@
 {
     const UnsignedArea& curr = get();
 
-    if (mBuffer)
-        mBuffer->updateBufferArea({static_cast<int32_t>(curr.width),
+    for (Hwc2TestVirtualBuffer* buffer : mBuffers)
+        buffer->updateBufferArea({static_cast<int32_t>(curr.width),
                 static_cast<int32_t>(curr.height)});
 }