Store previous theme in ExtensionInstallUI constructor (rather than ConfirmInstall) to ensure it always happens.
Store previous theme in ExtensionInstallUI constructor (rather than ConfirmInstall) to ensure it always happens.

BUG=65867
TEST=ui_tests and interactive_ui_tests and browser_tests

Review URL: http://codereview.chromium.org/6092009

git-svn-id: http://src.chromium.org/svn/trunk/src@70686 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2fa9bc76791d28ef712fbec49b6f295fac2638fc
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser