Revert of Port HistoryService::GetVisibleVisitCountToHost to CancelableTaskTracker

Revert of Port HistoryService::GetVisibleVisitCountToHost to CancelableTaskTracker (https://codereview.chromium.org/351553004/)

Reason for revert:
Failures on Linux ASAN LSan Tests (2):

OnPhishingDetectionDoneDisabled
OnPhishingDetectionDoneMultiplePings
OnPhishingDetectionDoneNotPhishing
OnPhishingDetectionDoneShowInterstitia

http://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20Tests%20%282%29/builds/4236

Original issue's description:
> Port HistoryService::GetVisibleVisitCountToHost to CancelableTaskTracker
> 
> Callback no longer receive a HistoryService::Handle, but instead client
> code should use the returned base::CancelableTaskTracker::TaskId to
> cancel an individual task.
> 
> Simplify implementation of BrowserFeatureExtractor as all the methods
> from HistoryService that are called uses base::CancelableTaskTracker by
> removing the mapping from HistoryService::Handle to request and using a
> scoped_ptr to deal with the lifetime of the ClientPhishingRequest object.
> 
> BUG=371818
> TBR=jochen
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=280110

TBR=blundell@chromium.org,jochen@chromium.org,bryner@chromium.org,noelutz@chromium.org,sdefresne@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=371818
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=280137

[leng, 2014-06-26 22:27:48]

Created Revert of Port HistoryService::GetVisibleVisitCountToHost to
CancelableTaskTracker

[commit-bot: I haz the power, 2014-06-26 22:31:29]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/leng@chromium.org/351363002/1

[commit-bot: I haz the power, 2014-06-26 22:33:52]

Change committed as 280137