Revert r229753 "Gesture recognizer must be a singleton accross all aura::RootWindows"

Breaks windows bots on chromium.webkit.
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20Builder/builds/44634

TBR=varunjain

Review URL: https://codereview.chromium.org/30813003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229761 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229761