Revert of Turn GoogleURLTrackerNavigationHelper(Impl) into a per-tab object.

Revert of Turn GoogleURLTrackerNavigationHelper(Impl) into a per-tab object. (https://codereview.chromium.org/283413002/)

Reason for revert:
Introduced flake on Mac: crbug.com/376550

Original issue's description:
> Turn GoogleURLTrackerNavigationHelper(Impl) into a per-tab object.
> 
> The goal of this CL is to eliminate the dependence of
> GoogleURLTracker(MapEntry) on NavigationController. To accomplish this goal,
> GoogleURLTrackerNavigationHelper is turned into a conceptually per-tab
> interface. GoogleURLTracker::OnNavigationPending() now takes in the
> GoogleURLTrackerNavigationHelper with which the navigation is associated rather
> than the associated NavigationController; GoogleURLTracker performs per-tab
> actions by calling the navigation helper associated with the tab.
> 
> A followup CL will turn GoogleURLTrackerNavigationHelper(Impl) into the
> GoogleURLTrackerDriver interface and ContentURLTrackerDriver implementation.
> 
> BUG=373230
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272094

TBR=pkasting@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=373230
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272503

[blundell, 2014-05-23 12:07:45]

Created Revert of Turn GoogleURLTrackerNavigationHelper(Impl) into a per-tab
object.

[commit-bot: I haz the power, 2014-05-23 12:08:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/blundell@chromium.org/294193005/1

[commit-bot: I haz the power, 2014-05-23 12:10:11]

Change committed as 272503

[Peter Kasting, 2014-05-23 17:29:03]

LGTM