Revert 110035 - Print Preview: Making margin selection sticky (part 2/2)

Revert 110035 - Print Preview: Making margin selection sticky (part 2/2)

This CL makes "Custom" margins sticky across different preview sessions but also within the same preview session.

Here is a summary of all changes.
- Within same preview session: So far selecting "Custom" was
  picking up from whatever the previous selected option was.
  Now, "Custom" remembers the specified margins. To test this
  select "Custom", do some dragging, then change to another
  option and back to "Custom".
- Across preview sessions: Select "Custom", do some dragging,
  then print. Open print preview again, the last used custom
  margins are remembered.
- There was a bunch of messages sent from JS to get various
  info/settings (initiator tab title, measurement system and
  number format, last used margin settings, default printer).
  I created a single message "getInitialSettings" to get all
  at once (they are needed before the 1st preview is is
  requested).

BUG=102446
TEST=See bug description.


Review URL: http://codereview.chromium.org/8351048

TBR=dpapad@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=110040