Revert of mac: History swiping doesn't work right with iframes.

Revert of mac: History swiping doesn't work right with iframes. (https://codereview.chromium.org/227043012/)

Reason for revert:
This CL causes regressions in vertical content scrolling.

https://code.google.com/p/chromium/issues/detail?id=365034

Original issue's description:
> mac: History swiping doesn't work right with iframes.
> 
> This CL is a reland of crrev.com/194713016. The reason that the previous
> attempt to land this CL failed was because Blink was claiming to handle events
> that it was actually ignoring. This has been fixed in crrev.com/219473003,
> which also added unit-tests to ensure that the new behavior is correct.
> 
> In addition, this reland removes all logic related to the isPinnedLeft and
> isPinnedRight properties of the history swiper. They are no longer required
> because they are a subset of the state that determines whether blink will
> handle an event, which is now being correctly propagated to the history swiper.
> This fixes a long outstanding bug (I don't think it's ever worked) where the
> pinned state is not correctly propagated to the history swiper, which prevents
> history navigation. (Blink only sends callbacks for when a user scrolls or the
> window is resized. If the user performs a history navigation, the pinned state
> might change, but Blink will not send a callback to update the state of the
> history swiper).
> 
> ----------------Description from first attempt to land this CL----------------
> 
> In the previous behavior, it was possible for a user to start scrolling an
> iframe with the touch pad, and then trigger history navigation. This happened
> because the Cocoa view only received callbacks for whether an event in a
> gesture wasn't handled. If any event in a gesture happened to not be handled by
> blink, then that event could trigger history swiping, even though blink may
> have handled earlier events in the same gesture!
> 
> My solution is to propagate the information for whether an event was handled to
> the Cocoa view. History swiping is only enabled if no event is ever handled by
> blink.
> 
> BUG=321437
> TEST=Navigate to www.google.com. Then navigate to
> http://codepen.io/anon/pen/ujsec. Place the cursor in the box that says "place
> cursor here", and start a downwards 2-finger swipe. Half way through the swipe,
> change directions and swipe to the left (or right, depending on your settings)
> to navigate backwards in history. Prior to this change, the history swipe arrow
> would appear. In this change, the history swipe arrow no longer appears.
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=262572

TBR=thakis@chromium.org,avi@chromium.org
BUG=321437
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=265548

[erikchen, 2014-04-22 23:11:58]

Created Revert of mac: History swiping doesn't work right with iframes.

[erikchen, 2014-04-22 23:12:52]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2014-04-22 23:13:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/erikchen@chromium.org/248383002/1

[Avi (use Gerrit), 2014-04-23 02:12:32]

lgtm

OK. :(

[commit-bot: I haz the power, 2014-04-23 06:13:07]

Change committed as 265548