[ServiceWorker] Set setSkipServiceWorker flag of the request from NPAPI plugins

We should not support ServiceWorker for NPAPI plugins.
It is because ServiceWorker can mislead these plugins and can cause security problems.

This CL sets setSkipServiceWorker flag at the constructor of PluginURLFetcher and WebPluginImpl::InitiateHTTPRequest() and WebPluginImpl::RouteToFrame().

BUG=413094

Review URL: https://codereview.chromium.org/618583003

Cr-Commit-Position: refs/heads/master@{#297616}
2 files changed