There are two different bugs contributing to this. One of these might be fixable via Finch the other one is not

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2a1ffdc2376233aaef5110a1c406a50539a795bd

commit 2a1ffdc2376233aaef5110a1c406a50539a795bd
Author: pkotwicz <pkotwicz@chromium.org>
Date: Wed Jan 25 19:56:13 2017

WebAPKs: Fix play-install variations check

This CL:
1) Fixes ChromeWebApkHost#canUseGooglePlayToInstallWebApk() to use
variations::GetVariationParamValueByFeature() instead of
variations::GetVariationParamValue(). This matches the server side variations
configuration.
2) Updates the cached value of whether WebAPKs are enabled (Returned by
ChromeWebApkHost#isEnabled()) prior to calling
ChromeWebApkHost#canUseGooglePlayToInstallWebApk().

BUG= 684804 

Review-Url: https://codereview.chromium.org/2655803002
Cr-Commit-Position: refs/heads/master@{#446097}

[modify] https://crrev.com/2a1ffdc2376233aaef5110a1c406a50539a795bd/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
[modify] https://crrev.com/2a1ffdc2376233aaef5110a1c406a50539a795bd/chrome/browser/android/chrome_jni_registrar.cc
[modify] https://crrev.com/2a1ffdc2376233aaef5110a1c406a50539a795bd/chrome/browser/android/webapk/chrome_webapk_host.cc
[modify] https://crrev.com/2a1ffdc2376233aaef5110a1c406a50539a795bd/chrome/browser/android/webapk/chrome_webapk_host.h

Testing steps for test team:
1) Turn off Android-Settings>Security>Unknown-Sources
2) Set Chrome command flags via set_chrome_command_line.py --enable-features="ImprovedA2HS" Script is available at https://pkotwicz.users.x20web.corp.google.com/www/chrome_command_line/set_chrome_command_line.py
3) Force stop Chrome, then launch Chrome. Repeat 2x

Expected:
"Turn on unknown sources" dialog is not shown

Actual:
"Turn on unknown sources" dialog is shown on second launch of Chrome

Deleted: dialog.png 84.2 KB

	dialog.png 84.2 KB View Download

Requesting merge to M-57. This CL has made it to Chrome Canary 58.0.2993.0

Your change meets the bar and is auto-approved for M57. Please go ahead and merge the CL to branch 2987 manually. Please contact milestone owner if you have questions.
Owners: amineer@(clank), cmasso@(bling), ketakid@(cros), govind@(desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c99788f98ca6aba368c4dc1431ddae2a9ccdbb26

commit c99788f98ca6aba368c4dc1431ddae2a9ccdbb26
Author: Peter Kotwicz <pkotwicz@google.com>
Date: Thu Jan 26 23:34:36 2017

WebAPKs: Fix play-install variations check

This CL:
1) Fixes ChromeWebApkHost#canUseGooglePlayToInstallWebApk() to use
variations::GetVariationParamValueByFeature() instead of
variations::GetVariationParamValue(). This matches the server side variations
configuration.
2) Updates the cached value of whether WebAPKs are enabled (Returned by
ChromeWebApkHost#isEnabled()) prior to calling
ChromeWebApkHost#canUseGooglePlayToInstallWebApk().

BUG= 684804 

Review-Url: https://codereview.chromium.org/2655803002
Cr-Commit-Position: refs/heads/master@{#446097}
(cherry picked from commit 2a1ffdc2376233aaef5110a1c406a50539a795bd)

Review-Url: https://codereview.chromium.org/2654093006 .
Cr-Commit-Position: refs/branch-heads/2987@{#129}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}

[modify] https://crrev.com/c99788f98ca6aba368c4dc1431ddae2a9ccdbb26/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
[modify] https://crrev.com/c99788f98ca6aba368c4dc1431ddae2a9ccdbb26/chrome/browser/android/chrome_jni_registrar.cc
[modify] https://crrev.com/c99788f98ca6aba368c4dc1431ddae2a9ccdbb26/chrome/browser/android/webapk/chrome_webapk_host.cc
[modify] https://crrev.com/c99788f98ca6aba368c4dc1431ddae2a9ccdbb26/chrome/browser/android/webapk/chrome_webapk_host.h

Issue 686392 has been merged into this issue.