Adding fixes and features for the Action Recorder Extension.

1. Fixed an edge case where the Recorder UI is truncated by the parent
page's stylesheet. Added an explicit padding style to the Recorder UI.
2. Record page load events on the main frame. I can later use the page
load events to truncate test recipes.
3. Add a typePassword action.

Bug: 855284
Change-Id: Ieac830addbc7dff303ab456438328ffd64e12953
Reviewed-on: https://chromium-review.googlesource.com/1145624
Commit-Queue: Yiming Zhou <uwyiming@google.com>
Reviewed-by: Jared Saul <jsaul@google.com>
Cr-Commit-Position: refs/heads/master@{#577771}
4 files changed