Change notification handling to prevent multiple 'Do you mean...?' infobars f...

Change notification handling to prevent multiple 'Do you mean...?' infobars from
displaying in a tab.  This could happen when the user types in a new query before
the AlternateNavURLFetcher was able to resolve the URL.

BUG=43378
TEST=Load two single word domains within quick succession in the same tab.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=49312

[csilv, 2010-06-09 19:29:01]

+estade for review
Evan, was able to reliably reproduce and then fix this issue via some rather
small changes include for review.  Currently alternate_nav_url_fetcher.cc does
not have a corresponding unit test, so this review may not be acceptable until I
create one, but I figured I'd get a head start on the review since it's marked
as P1.

[Evan Stade, 2010-06-09 19:46:11]

http://codereview.chromium.org/2747006/diff/3001/4001
File chrome/browser/alternate_nav_url_fetcher.cc (right):

http://codereview.chromium.org/2747006/diff/3001/4001#newcode45
chrome/browser/alternate_nav_url_fetcher.cc:45: } else if (!controller_) {
can the hypothetical else be reached (where controller_ is non null, but doesn't
match source)? what would that indicated?

[csilv, 2010-06-09 20:09:22]

http://codereview.chromium.org/2747006/diff/3001/4001
File chrome/browser/alternate_nav_url_fetcher.cc (right):

http://codereview.chromium.org/2747006/diff/3001/4001#newcode45
chrome/browser/alternate_nav_url_fetcher.cc:45: } else if (!controller_) {
On 2010/06/09 19:46:11, Evan Stade wrote:
> can the hypothetical else be reached (where controller_ is non null, but
doesn't
> match source)? what would that indicated?

Yes, that can happen if some other tab sends a NAV_ENTRY_PENDING notification
since we don't stop listening for it.  In that case we just ignore the
notification which is the desired behavior.

[Evan Stade, 2010-06-09 20:35:10]

LGTM