Changes to C++ protocol buffer compilation.

Generate C++ code for all .proto files before attempting
to compile them. This takes care of the case where generated
.pb.cc files include other header / c++ files due to proto
imports in the original .proto files.

Change-Id: I26513842618fd31f0b33a3f10df2a5e556094515
diff --git a/core/binary.mk b/core/binary.mk
index f20a6a6..f1ffca1 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -282,7 +282,7 @@
 
 $(proto_generated_cc_sources): PRIVATE_ARM_MODE := $(normal_objects_mode)
 $(proto_generated_cc_sources): PRIVATE_ARM_CFLAGS := $(normal_objects_cflags)
-$(proto_generated_objects): $(proto_generated_cc_sources_dir)/%.o: $(proto_generated_cc_sources_dir)/%.cc
+$(proto_generated_objects): $(proto_generated_cc_sources_dir)/%.o: $(proto_generated_cc_sources_dir)/%.cc $(proto_generated_headers)
 	$(transform-$(PRIVATE_HOST)cpp-to-o)
 -include $(proto_generated_objects:%.o=%.P)