[1.0] Replace Object.observe two-way data-binding

[micjamking]

DevTools Author's settings panel currently relies on Object.observe for two-way data-binding and communicating changes between the data model and the view.

app/scripts/panel.js#L232

  // Observe changes to panel model
  Object.observe(panel, observer, ['add', 'update']);

According to this Chrome status update and this update from TC39, Object.observe is being withdrawn from the ES7 spec. Subsequently, Object.observe is being pulled from Chrome and other V8-based environments (recently removed from Chrome v50).

Alternative solutions and recommendations:

• Object.defineProperty
• Object.observe polyfill
• Proxy object