The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/93ec7def5cee33305155e15131c439d23ddceb0d

commit 93ec7def5cee33305155e15131c439d23ddceb0d
Author: dougarnett <dougarnett@chromium.org>
Date: Wed Jul 20 15:51:25 2016

PrerenderingOffliner will abort background load if it sees chrome transitioning to foreground on low-end devices.
Also adds new FOREGROUND_CANCELED request status (and histogram enum value).

BUG= 627884 , 622508 

Review-Url: https://codereview.chromium.org/2149773002
Cr-Commit-Position: refs/heads/master@{#406565}

[modify] https://crrev.com/93ec7def5cee33305155e15131c439d23ddceb0d/chrome/browser/android/offline_pages/prerendering_offliner.cc
[modify] https://crrev.com/93ec7def5cee33305155e15131c439d23ddceb0d/chrome/browser/android/offline_pages/prerendering_offliner.h
[modify] https://crrev.com/93ec7def5cee33305155e15131c439d23ddceb0d/chrome/browser/android/offline_pages/prerendering_offliner_unittest.cc
[modify] https://crrev.com/93ec7def5cee33305155e15131c439d23ddceb0d/components/offline_pages/background/offliner.h
[modify] https://crrev.com/93ec7def5cee33305155e15131c439d23ddceb0d/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6dd8c1ec9f9c9339676e83374eb78c627fc4aa1e

commit 6dd8c1ec9f9c9339676e83374eb78c627fc4aa1e
Author: dougarnett <dougarnett@chromium.org>
Date: Thu Jul 21 15:54:19 2016

[OfflinePages] Do not start background loading on low-end devices if app has any visible Activities.

BUG= 627884 ,  622508 

Review-Url: https://codereview.chromium.org/2164503003
Cr-Commit-Position: refs/heads/master@{#406864}

[modify] https://crrev.com/6dd8c1ec9f9c9339676e83374eb78c627fc4aa1e/base/android/java/src/org/chromium/base/SysUtils.java
[modify] https://crrev.com/6dd8c1ec9f9c9339676e83374eb78c627fc4aa1e/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundOfflinerTask.java
[modify] https://crrev.com/6dd8c1ec9f9c9339676e83374eb78c627fc4aa1e/chrome/android/junit/src/org/chromium/chrome/browser/offlinepages/BackgroundOfflinerTaskTest.java