[headless] Use embedded v8 data for headless.

R=alexclarke@chromium.org,skyostil@chromium.org,torne@chromium.org
BUG=610673

Review-Url: https://codereview.chromium.org/1962343002
Cr-Commit-Position: refs/heads/master@{#416371}

build/args/headless.gn

@@ -16,6 +16,10 @@ ozone_platform_headless = true
 # into binary.
 icu_use_data_file = false
 
+# Use embedded data instead external files for headless in order
+# to simplify deployment.
+v8_use_external_startup_data = false
+
 enable_basic_printing = false
 enable_nacl = false
 enable_print_preview = false