Enable interactive_ui_tests

 * changed DCHECK in tree_node_model to make it easy to find how it failed.
 * Fixed compilation error in find_bar_host_interactive_uitest.cc on linux/views.
 * Disabled BrowserKeyEventsTest.AccessKeys for Chromeos
   Added/Changed ui_test_utils::RunAllPendingInMessageLoop where necessary.
 * Disabled tab_dragging_tests. I included the source so that we can catch
   compilation error even if tests do not run. Changed the comment from // -> /*
   as GCC complains the use of "\" (and potentially dangerous)
 * Added SleepInMessageLoop to allow event loop to execute the tasks/events
   while waiting.
 * For RunAllPendingInMessageLoop change, please see
   http://codereview.chromium.org/1591004

BUG=39736
TEST=interactive_ui_tests should pass with following cls
http://codereview.chromium.org/1594003
http://codereview.chromium.org/1545011.

Review URL: http://codereview.chromium.org/1576008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@43701 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed