GitLab

Remove |kAltInstantURLPath| from search.cc and retain the default Instant search base url path when the |kUseAltInstantURL| flag is enabled. 

BUG=382694
TEST=Run chrome with the following field trial flag and observe the Instant search base page url.
     --force-fieldtrials="EmbeddedSearch/Group1 use_alternate_instant_url:1 /"

Review URL: https://codereview.chromium.org/453573002

Cr-Commit-Position: refs/heads/master@{#289046}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289046 0039d316-1c4b-4281-b951-d872f2087c98