[login_manager] Start chrome with opencryptoki flag if user enables the lab

Change-Id: I0cfffd6abe2528bb92debb4aea38fd4bd4055cb5

R=cmasone@chromium.org
BUG=chromium-os:12416
TEST=
default mode, no flag added
with file, --load-opencryptoki added

Review URL: http://codereview.chromium.org/6877059
diff --git a/session_manager_setup.sh b/session_manager_setup.sh
index 94d3e7f..76766db 100755
--- a/session_manager_setup.sh
+++ b/session_manager_setup.sh
@@ -251,6 +251,12 @@
   fi
 fi
 
+# TODO(crosbug.com/14277): Make this a default.
+PKCS11_FLAGS=
+if [ -r "/home/chronos/.cryptohome-init-pkcs11" ]; then
+  PKCS11_FLAGS=--load-opencryptoki
+fi
+
 # Use OpenGL acceleration flags except on ARM
 if [ "$(uname -m)" != "armv7l" ] ; then
   ACCELERATED_FLAGS="--enable-accelerated-layers"
@@ -335,4 +341,5 @@
             ${FLASH_FLAGS} \
             ${SCREENSAVER_FLAG} \
             ${SKIP_OOBE} \
+            ${PKCS11_FLAGS} \
 -- "$WM_SCRIPT"