Ship Shadow DOM

Intent to Ship thread: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/ay9tVGRa8Rg

BUG=336121

Review URL: https://codereview.chromium.org/153483002

git-svn-id: svn://svn.chromium.org/blink/trunk@169201 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unused member functions of FormSubmission class.

This CL removes:
 - contentType
 - boundary
 - referrer
 - origin

BUG=none
TEST=none; no behavior changes

Review URL: https://codereview.chromium.org/195943019

git-svn-id: svn://svn.chromium.org/blink/trunk@169202 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Clean up FormState class.

- Remove unused m_textFieldValues and related code.
- Remove Document argument of the constructor
  It's always the owner Document of another argument.
- Make PassRefPtr<HTMLFormElement> argument a reference.
  We don't need to use PassRefPtr here, and the argument is always non-null.
- Remove unnecessary #include "FormState.h".

BUG=none
TEST=none; no behavior changes.

Needs rebase later

Review URL: https://codereview.chromium.org/198853003

git-svn-id: svn://svn.chromium.org/blink/trunk@169203 bbb929c8-8fbe-4397-9dbb-9b2b20218538