Don't work with FF49

[sdavidg]

"Handler function threw an exception: TypeError: this.tooltip is undefined
Stack: DataTooltip.prototype.show<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://firequery-at-binaryage-dot-com/lib/data-tooltip.js:68:5
exports.makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/ThreadSafeDevToolsUtils.js:101:14
InspectorOverlay<.onClickTooltip/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://firequery-at-binaryage-dot-com/lib/inspector-overlay.js:255:7
Handler.prototype.process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:937:23
this.PromiseWalker.walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:816:7
this.PromiseWalker.scheduleWalkerLoop/<@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:750:11
Line: 68, column: 5"

[janodvarko]

This bug is probably the culprit:
https://bugzilla.mozilla.org/show_bug.cgi?id=1267414

Honza

[janodvarko]

So, the right way to go here is probably create new Tooltip instance and not touch internals of the MarkupView, which can change.

Note:
Render tooltip content using React component
https://bugzilla.mozilla.org/show_bug.cgi?id=1306291

Honza