Move chrome.downloads out of experimental to dev

chrome/common/extensions/docs/samples.json

 {
   "api": {
     "chrome.bookmarks.create": "bookmarks.html#method-create",
     "chrome.bookmarks.get": "bookmarks.html#method-get",
     "chrome.bookmarks.getChildren": "bookmarks.html#method-getChildren",
     "chrome.bookmarks.getRecent": "bookmarks.html#method-getRecent",
     "chrome.bookmarks.getSubTree": "bookmarks.html#method-getSubTree",
     "chrome.bookmarks.getTree": "bookmarks.html#method-getTree",
     "chrome.bookmarks.move": "bookmarks.html#method-move",
     "chrome.bookmarks.onChanged": "bookmarks.html#event-onChanged",
@@ skipping 44 matching lines @@
     "chrome.devtools.inspectedWindow.eval": "devtools.inspectedWindow.html#method-eval",
     "chrome.devtools.inspectedWindow.getResources": "devtools.inspectedWindow.html#method-getResources",
     "chrome.devtools.inspectedWindow.onResourceAdded": "devtools.inspectedWindow.html#event-onResourceAdded",
     "chrome.devtools.inspectedWindow.onResourceContentCommitted": "devtools.inspectedWindow.html#event-onResourceContentCommitted",
     "chrome.devtools.inspectedWindow.reload": "devtools.inspectedWindow.html#method-reload",
     "chrome.devtools.network.getHAR": "devtools.network.html#method-getHAR",
     "chrome.devtools.network.onNavigated": "devtools.network.html#event-onNavigated",
     "chrome.devtools.network.onRequestFinished": "devtools.network.html#event-onRequestFinished",
     "chrome.devtools.panels.create": "devtools.panels.html#method-create",
     "chrome.devtools.panels.setOpenResourceHandler": "devtools.panels.html#method-setOpenResourceHandler",
+    "chrome.downloads.download": "downloads.html#method-download",
     "chrome.experimental.app.clearAllNotifications": "experimental.app.html#method-clearAllNotifications",
     "chrome.experimental.app.notify": "experimental.app.html#method-notify",
     "chrome.experimental.devtools.audits.addCategory": "experimental.devtools.audits.html#method-addCategory",
     "chrome.experimental.devtools.console.addMessage": "experimental.devtools.console.html#method-addMessage",
     "chrome.experimental.devtools.console.getMessages": "experimental.devtools.console.html#method-getMessages",
     "chrome.experimental.devtools.console.onMessageAdded": "experimental.devtools.console.html#event-onMessageAdded",
     "chrome.experimental.extension.onInstalled": "experimental.extension.html#event-onInstalled",
     "chrome.experimental.fontSettings.getFontList": "experimental.fontSettings.html#method-getFontList",
     "chrome.experimental.fontSettings.getFontName": "experimental.fontSettings.html#method-getFontName",
     "chrome.experimental.fontSettings.setFontName": "experimental.fontSettings.html#method-setFontName",
@@ skipping 2405 matching lines @@
         "manifest.json",
         "popup.html",
         "popup.js",
         "sample.css"
       ],
       "source_hash": "8e51dc3a9577065d22ce92f3c838edc5ceaf4e65",
       "zip_path": "examples\/api\/extension\/isAllowedAccess.zip"
     }
   ]
 }