Switch to libsigchain.a

  Use LOCAL_WHOLE_STATIC_LIBRARIES to instruct static linker
  to export symbols from the static library.

(cherry picked from commit 4340a14fbfe761a46e7a655b568cbd0953773df3)

Bug: 18701723
Change-Id: I70f6fdb64b0d1adbadf96c8de85870a903ec186a
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 76545f3..eade2e2 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -115,15 +115,11 @@
 include $(CLEAR_VARS)
 
 LOCAL_LDFLAGS := -Wl,--version-script,art/sigchainlib/version-script.txt -Wl,--export-dynamic
-LOCAL_CFLAGS:= -DLOG_TAG=\"SurfaceFlinger\" -Iart
+LOCAL_CFLAGS:= -DLOG_TAG=\"SurfaceFlinger\"
 LOCAL_CPPFLAGS:= -std=c++11
 
-# TODO: Trying to link libsigchain as a static library prevents
-# static linker from exporting necessary symbols. So as a workaround
-# we use sigchain.o
 LOCAL_SRC_FILES:= \
-	main_surfaceflinger.cpp \
-	sigchain_proxy.cpp
+	main_surfaceflinger.cpp
 
 LOCAL_SHARED_LIBRARIES := \
 	libsurfaceflinger \
@@ -133,6 +129,8 @@
 	libutils \
 	libdl
 
+LOCAL_WHOLE_STATIC_LIBRARIES := libsigchain
+
 LOCAL_MODULE:= surfaceflinger
 
 ifdef TARGET_32_BIT_SURFACEFLINGER