Bug 1051219 - Part I, Centralize the IMERender.setUpperCaseLock() call and skip if not rendered
Bug 1051219 - Part II, Centralize candidate rendering
Bug 1051219 - Part III, Move handleUpperCaseStateChange to renderingManager
Bug 1051219 - Part IV, Block IMERender calls if rendering is not updated yet
Merge pull request #24041 from timdream/keyboard-uppercase-rendering

Bug 1051219 - Block IMERender calls if rendering is not updated yet, r=rudyl