[safe browsing] Switch to independent cache lifetimes for gethash items.

[safe browsing] Switch to independent cache lifetimes for gethash items.

Previously cached gethash responses were valid either if the last update
was recent enough, or if the item itself were recent enough.  Switch to
supporting independent item lifetimes to prepare for API v3 (which sends
lifetime information from the server).

BUG=357763
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270003

[Scott Hess - ex-Googler, 2014-05-09 20:47:58]

Pull a bit more out of https://codereview.chromium.org/220493003

I can't think of any reason why this should not go into M-36 with no further
changes, but if you think of something, speak up!

[mattm, 2014-05-12 21:56:27]

lgtm with nit

https://codereview.chromium.org/280013002/diff/20001/chrome/browser/safe_brow...
File chrome/browser/safe_browsing/safe_browsing_database_unittest.cc (right):

https://codereview.chromium.org/280013002/diff/20001/chrome/browser/safe_brow...
chrome/browser/safe_browsing/safe_browsing_database_unittest.cc:29: TimeDelta
kCacheLifetime = TimeDelta::FromMinutes(45);
const?

[Scott Hess - ex-Googler, 2014-05-12 23:10:34]

const that lifetime

[Scott Hess - ex-Googler, 2014-05-12 23:10:48]

Thanks!

https://codereview.chromium.org/280013002/diff/20001/chrome/browser/safe_brow...
File chrome/browser/safe_browsing/safe_browsing_database_unittest.cc (right):

https://codereview.chromium.org/280013002/diff/20001/chrome/browser/safe_brow...
chrome/browser/safe_browsing/safe_browsing_database_unittest.cc:29: TimeDelta
kCacheLifetime = TimeDelta::FromMinutes(45);
On 2014/05/12 21:56:27, mattm wrote:
> const?

Sensible!

[Scott Hess - ex-Googler, 2014-05-12 23:10:52]

The CQ bit was checked by shess@chromium.org

[commit-bot: I haz the power, 2014-05-12 23:12:25]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/shess@chromium.org/280013002/40001

[commit-bot: I haz the power, 2014-05-13 03:48:48]

Change committed as 270003