Upgrade to Chromium 56.0.2924.87

[bbondy]

56.0.2924.76

https://github.com/brave/browser-laptop-bootstrap/tree/chromium56
https://github.com/brave/muon/tree/chromium56
https://github.com/brave/browser-laptop/tree/chromium56

[darkdh]

Known issues:

• Autofill not working (brave/muon@99d873a)
• Renderer crash when (brave/muon@30f457f)
  - navigating to the page from google search result
  - navigating to https://twitter.com
• Undefined symbols of v8 inspector on windows
• Unrecognized Content-Security-Policy directive 'referrer'. (8294031)
  - The CSP referrer directive is no longer supported in favor of the new Referrer-Policy header
• ERROR:entry.cc(167)] Entry::Deserialize: dictionary has no interface_provider_specs key on linux (Can't reproduce anymore)
  - Might related to https://bugs.chromium.org/p/chromium/issues/detail?id=677194
• chrome.contextMenus doesn't work (brave/muon@30a389c)
• cmd + \ of 1 password doesn't work (brave/muon@30a389c)
• fix dictionary look up from context menu (brave/muon@62dec3b)