Mojo: SimilarityTraits -> TypeConverter

Also Copy{From,To} -> Convert{From,To}.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/101743003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239379 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239379
Implement memory-persistent registration

This simply provides an in-memory registration in ServiceWorkerContext. It provides basic registration/unregistration,
adding stub ServiceWorkerRegistry and ServiceWorkerVersion classes.

BUG=285976
TBR=jam@chromium.org

Review URL: https://codereview.chromium.org/62203007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239380 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239380