Non flaky tests related to infobars with C++ delegates
Make them work with as ChromiumTestShellTestBase tests
Some small in place refactor
Fix some findbugs issues

Follow up downstream CL in https://gerrit-int.chromium.org/#/c/44963/

BUG=158817

Review URL: https://codereview.chromium.org/26378003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229143 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229143