Update description of fullscreen-within-tab experiment in about:flags.

BUG=256870

Review URL: https://codereview.chromium.org/165063002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251233 0039d316-1c4b-4281-b951-d872f2087c98
Creates a new helper function to extract search terms from the URL irrespective of the availability of InstantExtendedEnabledParam. 

Previously, InstantSearchPrerenderer invoked chrome::GetSearchTermsFromURL() to extract search terms from the search page url. chrome::GetSearchTermsFromURL() returns a valid non-empty string iff the url has an InstantExtendedEnabledParam("&espv"). If the query extraction is turned off, the search request url will not have an InstantExtendedEnabledParam. In those cases, chrome::GetSearchTermsFromURL() returns an empty string to the InstantSearchPrerenderer.

To extract search terms for InstantSearchPrerenderer, we should not depend on the query extraction flag or the Instant support state of the page.

Follow up of crrev.com/151813002.

BUG=none
TEST=none

Review URL: https://codereview.chromium.org/141893009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251234 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251233
Mojo: Add a threaded perf test for (local) message pipes.

R=sky@chromium.org

Review URL: https://codereview.chromium.org/164693002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251235 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251235