[win] Add flags to touch events. Enables Ctrl-tap.

BUG=335898

Review URL: https://codereview.chromium.org/142443002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246335 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246335
Fix build of key & touch unittests after r246207

The constructor signature changed.

TBR=rjkroege
TEST=events_unittests
NOTRY=true

Review URL: https://codereview.chromium.org/138163017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246336 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246336