Bug 1016184 - Part 3a: Fix typos and minor style changes. r=ehsan

Also group the private section together, and remove the protect section
since TouchCaret is a MOZ_FINAL class.
Bug 1016184 - Part 3b: Revise touch caret visibility logic. f=pchang, r=ehsan

* Refactor UpdateTouchCaret() into smaller functions.
* Update touch caret in PresShell::DidDoReflow() and
  PresShell::UnsuppressAndInvalidate() if needed.
Bug 1016184 - Part 3c: Fix test_focus_disabled.html. r=ehsan

Move the witness down so that touch caret won't cover other elements
when witness is focused().
Bug 1016184 - Part 3d: Fix test_bug644768.html. r=ehsan

Rename test_bug644768.html to bug644768.html, and change the original
test_bug644768.html to an iframe container.

Thank Steven Lee <slee@mozilla.com> for the original WIP patch.
Bug 1016184 - Part 3e: Fix test_reftests_with_caret.html. r=ehsan

Turn off the touch caret preference to fix test cases that ought to be
failed by definition of the touch caret behavior.

Thank Steven Lee <slee@mozilla.com> for the original WIP patch.
Bug 1016184 - Part 3f: Fix test_paste_selection.html. r=ehsan

Thank Olli Pettay <bugs@pettay.fi> for suggesting
sendMouseEventToWindow(). This is a tremendous help!
Bug 1016184 - Part 3g: Disable auto-hide feature in mochitest and reftest. r=ehsan
Bug 1016184 - Part 3h: Fix horizontal scroll bar appears. r=roc

The touch caret frame is initialized at (0, 0). When <html> or <body>
has dir="rtl", "margin-left: -15px" (in ua.css) makes the horizontal
scroll bar appear even if the touch caret is invisible.

To compensate this, make width, height, and margin be 0px when the touch
caret is invisible.
Bug 1036992 - Split up test_seek.html into multiple tests. r=cpearce

--HG--
rename : content/media/test/test_seek2.html => content/media/test/test_invalid_seek.html