Dependency Upgrades

• Squirrel.Mac, Electron's bundled
  macOS auto updater library, was upgraded to 0.3.0 which includes several bug
  fixes. The new version enables App Transport Security (ATS)
  on all requests it makes to the update server. This can be disabled,
  if needed, by adding NSAllowsArbitraryLoads to the app's plist file. #7933

New APIs

• You can now enable the macOS vibrancy effect on a BrowserWindow by calling
  setVibrancy(vibrancyType) or by including a vibrancy value in the
  constructor options. #7898
• You can now specify POST data when calling BrowserWindow.loadURL via the
  postData option. Also <form> tags configured with method=post will now
  make POST requests with their data when submitted. #7540
• The certificate specified to the session.setCertificateVerifyProc callback
  now includes the entire certificate chain. #7917
• The <webview> tag now supports a disableguestresize attribute that will
  disable automatic resizing of the guest webContents when the <webview>
  element resizes. You can now call setSize directly on the guest
  webContents to manually control the size. #7658
• The chrome.storage.remove and chrome.storage.clear APIs are now available
  to DevTools extensions. #7923

Bug Fixes

• The about: protocol is now correctly supported by default. #7908
• Menu item keyboard accelerators are now properly disabled when the menu item
  is disabled. #7962
• The check for disabling ASAR support via the ELECTRON_NO_ASAR environment
  variable is now cached for better performance. #7978
• Fixed a crash when calling app.setAboutPanelOptions(options) with a
  credits value. #7979
• Fixed an issue where an error would be thrown in certain cases when accessing
  remote objects or functions. #7980
• [SECURITY] Fixed an issue where the window.opener API did not behave as expected.