Added devtools_protocol_constants_generator.py.

BUG=308512

Review URL: https://codereview.chromium.org/108343003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242615 0039d316-1c4b-4281-b951-d872f2087c98
Fix the notification messages for Chrome OS update check.

The messages to notify users that the Chrome OS update requires certain
types of network connection, in the cases where update over a cellular
network is allowed and disallowed, were flipped. This CL swaps the value
of IDS_UPGRADE_NETWORK_LIST_CELLULAR_ALLOWED and
IDS_UPGRADE_NETWORK_LIST_CELLULAR_DISALLOWED.

BUG=330354

Review URL: https://codereview.chromium.org/120043006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242616 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242616