27899 Embed OCMock and iOS tests into IosUnitTests app (platform-ios, cla: yes, waiting for tree to go green)

27900 Remove references to deprecated SkClipOps (cla: yes, waiting for tree to go green, needs tests)

27901 Roll Skia from b806da450199 to 36aef96fec47 (1 revision) (cla: yes, waiting for tree to go green)

27902 Roll Skia from 36aef96fec47 to 337e4848397d (1 revision) (cla: yes, waiting for tree to go green)

27903 Roll Dart SDK from 96fdaff98f48 to 5406f286f566 (5 revisions) (cla: yes, waiting for tree to go green)