Added main menu press action
Auto-test
Successfully opening New Project dialog via menu.  Had to add mouseover event dispatch in addition to click event.
Refactored dialog testing class to have ability to find / click buttons based on title or id.  Added searching of shadow-dom to button finding method.
Reenabled first test, and created test for new project dialog (just open and close via x button).
Reorganized everything into access vs tester (to abstract functionality which will be used for extension)
Switched singleton to use factory and fixed recursion problem.
resolved conflict
Moved code to ui_access file and resolved errors.  Setup testing for git clone dialog as well.
Trying to check for visibility with `elementFromPoint`
Setup transitions event and separated menu access from SparkUIAccess to its own SparkMenuAccess to avoid stack overflow when initializing.  Added transition-complete to spark_overlay
Restored first-start about dialog.  Commented about removed assurance of about-dialog.  Added about dialog close-via-x test.  Added constructor to DialogTester to get by id (will probably enclose reference in SparkMenuAccess kind of class)
Added dialog accessors and moved what was SparkMenuAccess back into SparkUIAccess (makes more sense).  Reorganized per closest style guide
Cleanup
Revert "Auto-test"

This reverts commit d4702de4f47d3a91d45cc044616c126df08f90ca.
Fixed tests for initial state of no project root selected.  Verifying ok-cancel dialog for selecting project root instead of new-project and git-clone dialogs.
Review fixes
More review fixes
Resolved conflicts
Merge pull request #2908 from dart-lang/umop-testing-ui-dialogs

Testing closing of several dialogs