Add tooltip to new tab icon in tx-view

app/_locales/en/messages.json

@@ -599,6 +599,9 @@
   "oldUIMessage": {
     "message": "You have returned to the old UI. You can switch back to the New UI through the option in the top right dropdown menu."
   },
+  "openInTab": {
+    "message": "Open in tab"
+  },
   "or": {
     "message": "or",
     "description": "choice between creating or importing a new account"

ui/app/components/tx-view.js

@@ -138,10 +138,14 @@ TxView.prototype.render = function () {
 
       h(SelectedAccount),
 
-      !isMascara && h('div.open-in-browser', {
-        onClick: () => global.platform.openExtensionInBrowser(),
-      }, [h('img', { src: 'images/popout.svg' })]),
-
+      !isMascara && h(Tooltip, {
+        title: t('openInTab'),
+        position: 'bottom',
+      }, [
+        h('div.open-in-browser', {
+          onClick: () => global.platform.openExtensionInBrowser(),
+        }, [h('img', { src: 'images/popout.svg' })]),
+      ]),
     ]),
 
     this.renderHeroBalance(),