Revert 256843 "fix"

> fix

TBR=ben@chromium.org

Review URL: https://codereview.chromium.org/196383006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256844 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256844
Revert "Move wm/core to wm namespace."

This reverts commit 521c703f8d62fa698c3e88287c64d8d23f9ac675.

Broke gyp

BUG=

Review URL: https://codereview.chromium.org/199263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256846 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256846