Round app icon corners for bookmark apps in the launcher.

Bookmark apps can currently get square icons. This CL rounds the icons
when displaying them in the app launcher.

BUG=315632

Review URL: https://codereview.chromium.org/135533006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247580 0039d316-1c4b-4281-b951-d872f2087c98
Fix dragging onto shortcuts in the volume list.

The previous patch had a bug. Instead of modelItem.entry, entry was used, which was always undefined.

TEST=Tested manually.
BUG=337575

Review URL: https://codereview.chromium.org/143653014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247581 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247581