[android_webview] Exclude known incompatible code from check.

The AOSP bot doesn't delete incompatibly licensed code from the main
Chromium src/ directory which means the check that we run there should
ignore the folders from the KNOWN_INCOMPATIBLE list.

BUG=329540

Review URL: https://codereview.chromium.org/147293005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248270 0039d316-1c4b-4281-b951-d872f2087c98
Add a minimum required version to the webapp manifest to ensure that native messaging is supported.

BUG=309844

Review URL: https://codereview.chromium.org/150423003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248271 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248271