chaps: Remove libbase_ver override in gyp file.

CL:194476 modified platform2 to build against libchrome-242728. The
libbase_ver override in the gyp file is no longer needed.

This CL also updates the fallback version of BASE_VER in Makefile from
180609 to 242728.

BUG=chromium:361748
TEST=`FEATURES=test emerge-$BOARD platform2`
TEST=Verify that chapsd is linked against libchrome-242728.

Change-Id: I14177a61796c877765cbd8ff2dd3441ebe4699d1
Reviewed-on: https://chromium-review.googlesource.com/195281
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/Makefile b/Makefile
index d35cba4..f34355c 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@
 LIB_DIR ?= /usr/lib
 PAM_MODULE_DIR ?= /lib/security
 
-BASE_VER ?= 180609
+BASE_VER ?= 242728
 PC_DEPS = dbus-c++-1 protobuf openssl \
 	libchrome-$(BASE_VER) libchromeos-$(BASE_VER)
 PC_CFLAGS := $(shell $(PKG_CONFIG) --cflags $(PC_DEPS))
diff --git a/chaps.gyp b/chaps.gyp
index e88a310..dcd74c7 100644
--- a/chaps.gyp
+++ b/chaps.gyp
@@ -1,7 +1,6 @@
 {
   'variables': {
     'build_chaps_live_tests': 0,
-    'libbase_ver': 242728,
   },
   'target_defaults': {
     'dependencies': [