Explicitly delete the undesirable template instantiation of toV8.
Explicitly delete the undesirable template instantiation of toV8.

[1] added a non-implemented function in order to avoid an undesirable template
application. But instead of just not implementing, we can explicitly delete the
function. It is more desirable because it is easier to understand the intention
and violation will be detected in complie-time, not in link-time.

1: https://src.chromium.org/viewvc/blink?view=rev&revision=194789

BUG=None
R=tasak@google.com

Review URL: https://codereview.chromium.org/1153053003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@195957 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk