Support for mousecontrol script

Create a common pointer_settings::SetSensitivity call applicable to all input pointer devices.
Pull common code for mouse and touchpad into common functions.
Add calls for mouse status, swap left-right and sensitivity.

BUG=chromium-os:22305
TEST=plug in a mouse on a chromeos device. Mouse settings should appear in chrome://settings/system. Swap and pointer speed should work as expected.
Review URL: https://chromiumcodereview.appspot.com/9250023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@118409 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed