If a custom SecurityOrigin is set for a request, honor it in ResourceFetcher

XMLHttpRequest sets a special SecurityOrigin when it is constructed from an
isolated world. DocumentThreadableLoader uses this SecurityOrigin, but it is
not exposed to ResourceFetcher.

BUG=295829
TEST=http/tests/xmlhttprequest/xhr-to-blob-in-isolated-world.html

Review URL: https://codereview.chromium.org/107353003

git-svn-id: svn://svn.chromium.org/blink/trunk@163368 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Moving fontSelector from StyleResolver to StyleEngine.

To avoid dispatching fontLoaded event multiple times for the same font (caused by clearResolver), we should change fontSelector's owner.

BUG=236298,305885

Review URL: https://codereview.chromium.org/87503003

git-svn-id: svn://svn.chromium.org/blink/trunk@163369 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove WTF_LOG_VERBOSE macro

Remove WTF_LOG_VERBOSE macro as was suggested at https://codereview.chromium.org/95303002/, since this macro is not used anywhere.

Review URL: https://codereview.chromium.org/108043003

git-svn-id: svn://svn.chromium.org/blink/trunk@163370 bbb929c8-8fbe-4397-9dbb-9b2b20218538