Re-land r248110 "[Password Generation] Enable new UI"

Replaces key icon and associated bubble with autofill style dropdown. Changes include

- Update PasswordGenerationAgentTest
- Add interactive_uitest for new UI.
- Sync edits to confirmation password field(s).
- Update UMA stats to more accurately reflect user choices.

Updating the generation popup to match the latest mocks and implement the
editing popup will come in a later CL.

This reverts r248119 and fixes a use-after-free in
PasswordGenerationPopupControllerImpl::PossiblyAcceptPassword()

[email protected], [email protected]
[email protected], [email protected], [email protected]
BUG=318977

Review URL: https://codereview.chromium.org/151503006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248297 0039d316-1c4b-4281-b951-d872f2087c98
29 files changed