importer: Move chrome/browser/importer/importer.[cc,h] to importer_host.[cc,h].

This is the first change in preparation for splitting importer_host.[cc,h] into
importer_host.[cc,h] and importer.[cc,h].

With this I'll be able to move the Importer class, in a followup CL, to importer.[cc,h]. Otherwise that will be harder and a mess.

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/6652015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@77464 0039d316-1c4b-4281-b951-d872f2087c98
31 files changed