Malay, please merge the CL to M53 once it's landed.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/37970403bf95114d1c6659e618be8e43f4e343cd

commit 37970403bf95114d1c6659e618be8e43f4e343cd
Author: malaykeshav <malaykeshav@chromium.org>
Date: Sat Jul 02 01:13:13 2016

Filters out URL clicks based on host matching only.

This is a very basic implementation of clank's
ExternalNavigationHandler.ShouldOverrideUrlLoadingInternal().
Currently it only matches the referrer's host name to the host name of
the target URL.

COMPONENT=ChromeOS, Arc
BUG= 624950 

Review-Url: https://codereview.chromium.org/2113123002
Cr-Commit-Position: refs/heads/master@{#403586}

[modify] https://crrev.com/37970403bf95114d1c6659e618be8e43f4e343cd/chrome/browser/chromeos/arc/arc_navigation_throttle.cc
[modify] https://crrev.com/37970403bf95114d1c6659e618be8e43f4e343cd/chrome/browser/chromeos/arc/arc_navigation_throttle.h

bulk verified