Revert of Clean up GestureEventDetails constructors

Revert of Clean up GestureEventDetails constructors (patchset #4 id:100001 of https://codereview.chromium.org/565583005/)

Reason for revert:
This seems to fail the following tests in "athena_unittests" on "Linux ChromiumOS Tests (dbg)(3)"

- HomeCardGestureManagerTest.Basic
- HomeCardGestureManagerTest.StartCentered

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%283%29/builds/36778

Original issue's description:
> Clean up GestureEventDetails' constructors.
>
> In one of the GestureEventDetails' constructors, the arguments
> delta_x, delta_y sometime are not used, so we should make a new
> constructor which only takes one argument EventType.
>
> BUG=350942
>
> Committed: https://crrev.com/b5e408e7bffd3d1e6b60612f65c0538a90329c59
> Cr-Commit-Position: refs/heads/master@{#294760}

TBR=tdresser@chromium.org,jdduke@chromium.org,sadrul@chromium.org,sky@chromium.org,lanwei@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=350942
Committed: https://crrev.com/bedd69525d5dd70a953f7a8a49089de0d66fe148
Cr-Commit-Position: refs/heads/master@{#294776}

[nhiroki, 2014-09-15 01:48:43]

Created Revert of Clean up GestureEventDetails constructors

[commit-bot: I haz the power, 2014-09-15 01:49:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/572593002/1

[commit-bot: I haz the power, 2014-09-15 01:51:31]

Committed patchset #1 (id:1) as 02152ced24411e8411309a70cd31fd99918882a5

[commit-bot: I haz the power, 2014-09-15 01:54:03]

Patchset 1 (id:??) landed as
https://crrev.com/bedd69525d5dd70a953f7a8a49089de0d66fe148
Cr-Commit-Position: refs/heads/master@{#294776}