In order to check whether WebAPKs are enabled we need native. So we cache whether WebAPKs are enabled in preferences. When a user "Clears all data" this preference gets cleared too.

After a user "Clears all data", WebAPKs will start in a tab the first time (unless the user has launched Chrome after "Clearing all Data") and start as a WebAPK every subsequent time

Once we get rid of the variations experiment WebAPKs will start as WebAPKs after a user has "Cleared all Data" even if Chrome was not launched after the user "Cleared all Data"

Thanks Peter!

Reopenign this bug. This is definitely a user annoyance. Leaving it available so that we don't loose track of it.

Peter mentioned a CL to do this in the works

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/001f557bcaa2a1064874b69e67b1e30c2688cad0

commit 001f557bcaa2a1064874b69e67b1e30c2688cad0
Author: pkotwicz <pkotwicz@chromium.org>
Date: Thu Jul 06 20:05:43 2017

[Android WebAPK] Make variations only control whether WebAPKs can be installed

Previously, variations controlled whether:
- WebAPKs could be installed
- Already installed WebAPKs would open as WebAPKs

This CL makes variations only control whether WebAPKs can be installed

BUG=738133, 739497,  695284 

Review-Url: https://codereview.chromium.org/2965233003
Cr-Commit-Position: refs/heads/master@{#484722}

[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/ServiceTabLauncher.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/init/ProcessInitializationHandler.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationPlatformBridge.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/javatests/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandlerTest.java
[modify] https://crrev.com/001f557bcaa2a1064874b69e67b1e30c2688cad0/chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebApkUpdateManagerTest.java