Finish shadow support in new reorderer/renderer

Now passes alphas and light radius, and correctly transforms light
center for layers.

Also fixes begin-frame/layer clears to be damage rect aware.

Change-Id: I3b1415cd7bf1518c510145ebebdb745f494a2542
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 4acad67..8565372 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -206,7 +206,9 @@
 LOCAL_MODULE_TAGS := tests
 LOCAL_SHARED_LIBRARIES := $(hwui_shared_libraries)
 LOCAL_STATIC_LIBRARIES := libhwui_static_null_gpu
-LOCAL_CFLAGS := $(hwui_cflags)
+LOCAL_CFLAGS := \
+        $(hwui_cflags) \
+        -DHWUI_NULL_GPU
 
 LOCAL_SRC_FILES += \
     unit_tests/CanvasStateTests.cpp \