Bug 962626 - Browser API: mozmetachanged triggered when a meta element is added to the dom., r=ehsan

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rename : dom/browser-element/mochitest/test_browserElement_inproc_Iconchange.html => dom/browser-element/mochitest/test_browserElement_inproc_Metachange.html
rename : dom/browser-element/mochitest/test_browserElement_oop_Iconchange.html => dom/browser-element/mochitest/test_browserElement_oop_Metachange.html