Web Inspector: ES6: Improved Console Support for Symbol Objects

Web Inspector: ES6: Improved Console Support for Symbol Objects
https://bugs.webkit.org/show_bug.cgi?id=141173

Reviewed by Timothy Hatcher.

Source/JavaScriptCore:

* inspector/protocol/Runtime.json:
New type, "symbol".

* inspector/InjectedScriptSource.js:
Handle Symbol objects in a few places. They don't have properties
and they cannot be implicitly converted to strings.

Source/WebInspectorUI:

* UserInterface/Protocol/RemoteObject.js:
(WebInspector.RemoteObject):
(WebInspector.RemoteObject.prototype._isSymbol):
Symbols have an objectId because it is a non-primitive that cannot be passed
by value, however it cannot have properties, so handle some cases.

* UserInterface/Views/LogContentView.css:
(.console-formatted-symbol):
Give Symbol's their own color.

LayoutTests:

* inspector/model/remote-object-expected.txt:
* inspector/model/remote-object.html:
Update the RemoteObject test to include Symbols.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@179659 268f45cc-cd09-0410-ab3c-d52691b4dbfc