Fix find_used_resources.py issue
Fix find_used_resources.py issue

The header file has different format when compiled with
enable_resource_whitelist_generation=1

BUG=546181
TBR=scottmg

Review URL: https://codereview.chromium.org/1516273002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#364780}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk