pageVisibilityState 1397 Source/core/dom/Document.cpp     return pageVisibilityStateString(pageVisibilityState());
pageVisibilityState 1402 Source/core/dom/Document.cpp     return pageVisibilityState() != PageVisibilityStateVisible;
pageVisibilityState 1411 Source/core/dom/Document.cpp     PageVisibilityState state = pageVisibilityState();
pageVisibilityState 1134 Source/core/dom/Document.h     PageVisibilityState pageVisibilityState() const;