[Retry] Remove linux_use_tcmalloc and switch to use_allocator in Blink.

It's retry of https://src.chromium.org/viewvc/blink?revision=172528&view=revision.

If this change breaks some bots, please try restarting the
bot before reverting it. http://crrev.com/264460 may not be
effective yet until restarting.

See https://src.chromium.org/viewvc/blink?revision=168591&view=revision,
the bug and http://crrev.com/255129 for the details.

BUG=345554

Review URL: https://codereview.chromium.org/260863004

git-svn-id: svn://svn.chromium.org/blink/trunk@173165 bbb929c8-8fbe-4397-9dbb-9b2b20218538