Break Layer class into Gl and Vulkan subclasses

Test: manual testing
Change-Id: Ibd2beed39de3ac6da7448e96496253cfe427dfbb
diff --git a/libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp b/libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp
index c8258f7..65a1dc3 100644
--- a/libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp
+++ b/libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp
@@ -17,6 +17,7 @@
 #include "SkiaOpenGLPipeline.h"
 
 #include "DeferredLayerUpdater.h"
+#include "GlLayer.h"
 #include "LayerDrawable.h"
 #include "renderthread/EglManager.h"
 #include "renderthread/Frame.h"
@@ -136,7 +137,7 @@
 
 DeferredLayerUpdater* SkiaOpenGLPipeline::createTextureLayer() {
     mEglManager.initialize();
-    Layer* layer = new Layer(mRenderThread.renderState(), 0, 0);
+    GlLayer* layer = new GlLayer(mRenderThread.renderState(), 0, 0);
     layer->generateTexture();
     return new DeferredLayerUpdater(layer);
 }