GitLab

Add "about" popup menu to the "mini-browser" WebViewBrowserActivity of WebViewShell.
Clicking on the menu item results in information about WebView and current webview
settings to be printed using reflection.

BUG=481508

Review URL: https://codereview.chromium.org/1128573002

Cr-Commit-Position: refs/heads/master@{#330937}