Fixed wrap-around in MapTo32bitsFrameId and added unit tests.

BUG=326625

Review URL: https://codereview.chromium.org/106183005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239316 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239316
[rAC, OSX] Default button should be blue button.

BUG=286526
R=isherman@chromium.org

Review URL: https://codereview.chromium.org/107103003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239317 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239317