Mined from test logs In browser/devtools/markupview/test/browser_markupview_mutation_02.js: const TEST_DATA = [{ desc: "Adding a new node should flash the new node", mutate: (doc, rootNode) => { let newLi = doc.createElement("LI"); <- Causes CPOW warning newLi.textContent = "new list item"; <- Causes CPOW warning rootNode.appendChild(newLi); <- Causes CPOW warning }, flashedNode: ".list li:nth-child(3)" }, { desc: "Removing a node should flash its parent", mutate: (doc, rootNode) => { rootNode.removeChild(rootNode.lastElementChild); <- Causes CPOW warning } }, { desc: "Re-appending an existing node should only flash this node", mutate: (doc, rootNode) => { rootNode.appendChild(rootNode.firstElementChild); <- Causes CPOW warning }, flashedNode: ".list .item:last-child" }, { desc: "Adding an attribute should flash the node", mutate: (doc, rootNode) => { rootNode.setAttribute("name-" + Date.now(), "value-" + Date.now()); <- Causes CPOW warning } }, { desc: "Editing an attribute should flash the node", mutate: (doc, rootNode) => { rootNode.setAttribute("class", "list value-" + Date.now()); <- Causes CPOW warning } }, { desc: "Removing an attribute should flash the node", mutate: (doc, rootNode) => { rootNode.removeAttribute("class"); <- Causes CPOW warning } }]; add_task(function*() { let {inspector} = yield addTab(TEST_URL).then(openInspector); // Make sure mutated nodes flash for a very long time so we can more easily // assert they do inspector.markup.CONTAINER_FLASHING_DURATION = 1000 * 60 * 60; info("Getting the <ul.list> root node to test mutations on"); let rootNode = getNode(".list"); let rootNodeFront = yield getNodeFront(".list", inspector); info("Selecting the last element of the root node before starting"); yield selectNode(".list .item:nth-child(2)", inspector); for (let {mutate, flashedNode, desc} of TEST_DATA) { info("Starting test: " + desc); info("Mutating the DOM and listening for markupmutation event"); let mutated = inspector.once("markupmutation"); let updated = inspector.once("inspector-updated"); mutate(content.document, rootNode); <- Causes CPOW warning yield mutated; info("Asserting that the correct markup-container is flashing"); let flashingNodeFront = rootNodeFront; if (flashedNode) { flashingNodeFront = yield getNodeFront(flashedNode, inspector); } yield assertNodeFlashing(flashingNodeFront, inspector); // Making sure the inspector has finished updating before moving on yield updated; } });

This is test only.

Inspector bug triage. Filter on CLIMBING SHOES Fixed by Bug 1252099.