Do not purge remote folder if extension is installed as unpacked and has a key

BUG=293947
TEST=manual (uninstall app from webstore -> purged, uninstall unpacked app w/o key -> purged, uninstall unpacked app with key -> not purged)

Review URL: https://chromiumcodereview.appspot.com/24072014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224656 0039d316-1c4b-4281-b951-d872f2087c98
Cleanup: Simplify PrintDialogGtk code a little bit.

Review URL: https://chromiumcodereview.appspot.com/24088014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224657 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224656
[CleanUp] Use base::STLSetDifference() in place of std::set_difference()

BUG=254066
TEST=net_unittests

Review URL: https://chromiumcodereview.appspot.com/24155002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224658 0039d316-1c4b-4281-b951-d872f2087c98
Make compositing sticky on a WebWidget

Once compositing is triggered, stay in compositing mode
for the remainder of the WebWidget's lifetime.

BUG=295072

Review URL: https://chromiumcodereview.appspot.com/24289002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224659 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224658
SVN changes up to revision 224659