GitLab

*src/athena
Change ShellAppActivity to accept both AppWindow and ShellAppWindow.
Implement AppsClient to create NativeAppWindow and AppDelegate instances.

*src/extensions/shell
Add a new method DefaultShellBrowserMainDelegate::CreateAppsClient() to inject athena's AppsClient.

*src/extensions/browser
Add missing dtor to extensions::AppsClient to destroy an instance with a base class pointer in DefaultShellBrowserMainDelegate.

BUG=387288
TBR=benwells@chromium.org for the addition of the missing dtor of extensions::AppsClient.

Review URL: https://codereview.chromium.org/552133003

Cr-Commit-Position: refs/heads/master@{#294363}