Do not reuse webcontent which associates constrained login page.

Previously if the login page was opened in avatar bubble the source will always be SOURCE_AVATAR_BUBBLE_SIGN_IN even though it was triggered in settings, so sync settings confirmation view was shown, which is a bug. After landing https://codereview.chromium.org/1473543002/ the access point (source) is correct (ACCESS_POINT_SETTINGS), but triggerd this problem when the login page is opened in avatar bubble (https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/webui/options/sync_setup_handler.cc&l=384).

BUG=567794

Review URL: https://codereview.chromium.org/1511023002

Cr-Commit-Position: refs/heads/master@{#364188}
1 file changed