[metrics] use libchromeos.pc

BUG=chromium-os:24959
TEST=build

Change-Id: I7038f5173c7b0949cbf88e6a9213d75e96ae142d
Signed-off-by: Elly Jones <ellyjones@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/14012
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/metrics/Makefile b/metrics/Makefile
index 072fb04..46711c8 100644
--- a/metrics/Makefile
+++ b/metrics/Makefile
@@ -5,8 +5,10 @@
 # Makefile for metrics utilities -- library, client and daemon
 #
 
-CCONFIG = $(shell $(PKG_CONFIG) --cflags dbus-1 glib-2.0 dbus-glib-1)
-LDCONFIG = $(shell $(PKG_CONFIG) --libs dbus-1 glib-2.0 gthread-2.0 dbus-glib-1)
+PC_DEPS = dbus-1 glib-2.0 dbus-glib-1 libchromeos
+
+CCONFIG = $(shell $(PKG_CONFIG) --cflags $(PC_DEPS))
+LDCONFIG = $(shell $(PKG_CONFIG) --libs $(PC_DEPS) gthread-2.0)
 
 CXXFLAGS += -Wall -Werror -fPIC -fno-exceptions $(CCONFIG)