activeMutationObservers  188 Source/core/dom/MutationObserver.cpp     if (activeMutationObservers().isEmpty())
activeMutationObservers  191 Source/core/dom/MutationObserver.cpp     activeMutationObservers().add(observer);
activeMutationObservers  266 Source/core/dom/MutationObserver.cpp     copyToVector(activeMutationObservers(), observers);
activeMutationObservers  267 Source/core/dom/MutationObserver.cpp     activeMutationObservers().clear();