Support buildLayer in new pipeline

bug:26561995
bug:27620686

Change-Id: I6c39f9a077e7e6002d3c01b8888238fd17b0f02a
diff --git a/libs/hwui/FrameBuilder.cpp b/libs/hwui/FrameBuilder.cpp
index b18836f..9c46c00 100644
--- a/libs/hwui/FrameBuilder.cpp
+++ b/libs/hwui/FrameBuilder.cpp
@@ -37,7 +37,8 @@
         const LightGeometry& lightGeometry, const Rect &contentDrawBounds, Caches& caches)
         : mCanvasState(*this)
         , mCaches(caches)
-        , mLightRadius(lightGeometry.radius) {
+        , mLightRadius(lightGeometry.radius)
+        , mDrawFbo0(!nodes.empty()) {
     ATRACE_NAME("prepare drawing commands");
 
     mLayerBuilders.reserve(layers.entries().size());