issue #5183, refactor UILayoutExecutant doLayout method
Revert "Revert "Merge pull request #6752 from andyque/refactorLayout""

This reverts commit 1ed9b9749ea80ca56d13538613673144b09a8c2f.
Merge branch 'fix_revert_pr' into refactor5183
Merge remote-tracking branch 'upstream/v3' into refactor5183
issue #5183, remove in class member initialization
Merge pull request #6894 from andyque/refactor5183

refactor Layout, LayoutParameter and LayoutExecutant