LEGACY_MOZILLA_REQUEST 2710 Source/core/dom/Element.cpp     FullscreenElementStack::from(document()).requestFullScreenForElement(this, (flags | LEGACY_MOZILLA_REQUEST), FullscreenElementStack::EnforceIFrameAllowFullScreenRequirement);
LEGACY_MOZILLA_REQUEST  152 Source/core/dom/FullscreenElementStack.cpp     bool inLegacyMozillaMode = (flags & Element::LEGACY_MOZILLA_REQUEST);