Mark inspector/extensions/extensions-resources.html as flaky
Mark inspector/extensions/extensions-resources.html as flaky

This tests is failing flakily at least on WebKit Win10.

BUG=602193
TBR=caseq@chromium.org

Review URL: https://codereview.chromium.org/1878553002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#386363}

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