Comment 1 for bug 1577168

Status on this bug after applying updates:

1. Activating Web Browser & Amazon App leads to Web Browser crashing but did not cause Ubuntu 16.04 to hang.

2. Below are associated reports from syslog. Hope it can reveal the causes of this problem.

May 10 23:14:31 Eliot gnome-session[1738]: Invalid webapp webapp definition: homepage not found or fails predicate isString
May 10 23:14:31 Eliot gnome-session[1738]: Could not open manifest file: "/usr/share/unity-webapps/userscripts/unity-webapps-amazon/manifest.json"
May 10 23:14:31 Eliot gnome-session[1738]: qml: Loading webview on /home/xxx/.local/share/ubuntu-amazon-default
May 10 23:14:31 Eliot gnome-session[1738]: Invalid webapp webapp definition: homepage not found or fails predicate isString
May 10 23:14:31 Eliot gnome-session[1738]: Could not open manifest file: "/usr/share/unity-webapps/userscripts/unity-webapps-amazon/manifest.json"
May 10 23:14:31 Eliot gnome-session[1738]: QQmlExpression: Expression file:///usr/share/webbrowser-app/webcontainer/WebApp.qml:272:25 depends on non-NOTIFYable properties:
May 10 23:14:31 Eliot gnome-session[1738]: unity::action::qml::ActionManager::globalContext
May 10 23:14:31 Eliot gnome-session[1738]: qml: Loaded 5 UA override(s) from file:///usr/lib/x86_64-linux-gnu/qt5/qml/Ubuntu/Web/ua-overrides-mobile.js
May 10 23:14:31 Eliot gnome-session[1738]: [0510/231431:ERROR:zygote_host_impl_linux.cc(162)] Failed to adjust OOM score of renderer with pid 8898: Permission denied
May 10 23:14:31 Eliot gnome-session[1738]: qml: Start browsing
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/webcontainer/ContentPickerDialog.qml:22:1: module "Ubuntu.Content" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/webcontainer/ContentDownloadDialog.qml:22:1: module "Ubuntu.Content" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/ContentHandler.qml:20:1: module "Ubuntu.Content" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/Downloader.qml:23:1: module "Ubuntu.Content" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/Downloader.qml:22:1: module "Ubuntu.DownloadManager" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/Downloader.qml:23:1: module "Ubuntu.Content" is not installed
May 10 23:14:31 Eliot gnome-session[1738]: file:///usr/share/webbrowser-app/Downloader.qml:22:1: module "Ubuntu.DownloadManager" is not installed
May 10 23:14:32 Eliot gnome-session[1738]: [0510/231432:ERROR:layer_tree_host_impl.cc(2218)] Forcing zero-copy tile initialization as worker context is missing
May 10 23:14:32 Eliot gnome-session[1738]: qml: Loaded 5 UA override(s) from file:///usr/lib/x86_64-linux-gnu/qt5/qml/Ubuntu/Web/ua-overrides-desktop.js