Move PermittedChromeSchemeHosts to ExtensionsClient.

BUG=298586
R=mpcomplete@chromium.org

Review URL: https://codereview.chromium.org/51373003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231933 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231933
Build "shell" target with chromium_code set.

This should enable all warnings that comes with chromium_code for this target.

BUG=None
TEST=ninja -C out/Debug shell
R=ben@chromium.org,derat@chromium.org

Review URL: https://codereview.chromium.org/50043004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231934 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231934