SF: Remove BufferStateLayer class

This CL removes the BufferStateLayer class and some of the references to
"BufferStateLayer" in factory and utility method names. In order to keep
the diff smaller, I'll send out a separate CL to remove the remaining
references.

Bug: 238781169
Test: refactor, existing tests pass

Change-Id: I62fe00caa87e109435da62329e817c19cfb96ead
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 91e32f3..e690aaf 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -65,7 +65,6 @@
 #include <mutex>
 #include <sstream>
 
-#include "BufferStateLayer.h"
 #include "DisplayDevice.h"
 #include "DisplayHardware/HWComposer.h"
 #include "FrameTimeline.h"
@@ -871,7 +870,7 @@
     float bufferWidth = getBufferSize(s).getWidth();
     float bufferHeight = getBufferSize(s).getHeight();
 
-    // BufferStateLayers can have a "buffer size" of [0, 0, -1, -1] when no display frame has
+    // Layers can have a "buffer size" of [0, 0, -1, -1] when no display frame has
     // been set and there is no parent layer bounds. In that case, the scale is meaningless so
     // ignore them.
     if (!getBufferSize(s).isValid()) {
@@ -3538,7 +3537,7 @@
 sp<Layer> Layer::createClone() {
     LayerCreationArgs args(mFlinger.get(), nullptr, mName + " (Mirror)", 0, LayerMetadata());
     args.textureName = mTextureName;
-    sp<BufferStateLayer> layer = mFlinger->getFactory().createBufferStateLayer(args);
+    sp<Layer> layer = mFlinger->getFactory().createBufferStateLayer(args);
     layer->mHwcSlotGenerator = mHwcSlotGenerator;
     layer->setInitialValuesForClone(sp<Layer>::fromExisting(this));
     return layer;