Adds a small icon to notifications, and connects it to synced notifications.

The small icon is a 16x16 image in the bottom right of all notification
templates.  Currently it is not exposed to the JS API, but instead is used
only by internal API systems (starting with synced notifications.)

BUG=284592

Review URL: https://codereview.chromium.org/149433005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247875 0039d316-1c4b-4281-b951-d872f2087c98
Wires through ScrollbarCorner to NativeTheme.

BUG=333499
TEST=none
R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/149513010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247876 0039d316-1c4b-4281-b951-d872f2087c98
[SyncFS] Don't re-run conflict resolution on resolution error

BUG=339327
R=kinuko@chromium.org, nhiroki@chromium.org

Review URL: https://codereview.chromium.org/149683008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247877 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247876
SVN changes up to revision 247877