Instant: Don't use the local overlay's URL for the NTP.

Instant: Don't use the local overlay's URL for the NTP.

GetInstantURL() is used for both the NTP as well as the overlay. So, it's wrong
for it to assume that it's okay to return the local overlay's URL under some
circumstances. Instead, it should return false, and have the caller fallback to
the local NTP's URL or local overlay's URL as appropriate.

BUG=224946
R=samarth@chromium.org
TEST=See bug.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=191967

[sreeram, 2013-04-01 23:28:12]

Please review.

[samarth, 2013-04-01 23:42:46]

Change looks good but please update the function comments in the .h file.  Also,
it took me a good five minutes to figure out what was going on here; please
clarify what the bug is in the change description.

Finally, no tests? :)

[samarth, 2013-04-01 23:43:06]

Oops, meant to lgtm as well.

[sreeram, 2013-04-02 20:20:19]

On 2013/04/01 23:42:46, samarth wrote:
> Change looks good but please update the function comments in the .h file. 
Also,
> it took me a good five minutes to figure out what was going on here; please
> clarify what the bug is in the change description.
> 
> Finally, no tests? :)

Done (updated .h comments and CL description; added a test).

[commit-bot: I haz the power, 2013-04-02 22:54:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sreeram@chromium.org/13162003/5001

[commit-bot: I haz the power, 2013-04-03 03:56:12]

Change committed as 191967