Remove safe-browsing false-positive tracking.

Remove safe-browsing false-positive tracking.

This code originally tracked false positives in BloomFilter.
PrefixSet doesn't have false positives in the same way, so the number
is misleading.

BUG=64988
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=234695

[Scott Hess - ex-Googler, 2013-11-05 22:29:43]

Was randomly reviewing bugs and realized this one was obsolete at this point.

[mattm, 2013-11-05 22:56:40]

lgtm

[Alexei Svitkine (slow), 2013-11-05 23:12:01]

histograms.xml lgtm

[commit-bot: I haz the power, 2013-11-06 00:27:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/60013005/1

[commit-bot: I haz the power, 2013-11-06 02:38:36]

Retried try job too often on win_rel for step(s) browser_tests,
chrome_frame_net_tests, chrome_frame_tests, chrome_frame_unittests,
content_browsertests, mini_installer_test, nacl_integration,
sync_integration_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-11-12 20:28:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/60013005/1

[commit-bot: I haz the power, 2013-11-12 23:34:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/60013005/1

[commit-bot: I haz the power, 2013-11-13 01:20:05]

Change committed as 234695