DevTools: format keys in object previews using sans serif.

third_party/WebKit/LayoutTests/inspector/console/console-format-collections-expected.txt

 CONSOLE MESSAGE: line 15: [object HTMLCollection]
 CONSOLE MESSAGE: line 19: [object HTMLCollection]
 CONSOLE MESSAGE: line 23: [object HTMLOptionsCollection]
 CONSOLE MESSAGE: line 27: [object HTMLAllCollection]
 CONSOLE MESSAGE: line 31: [object HTMLFormControlsCollection]
 CONSOLE MESSAGE: line 35: [object RadioNodeList]
 CONSOLE MESSAGE: line 41: 1,2,
 CONSOLE MESSAGE: line 44: [object Object]
 CONSOLE MESSAGE: line 51: [object Arguments]
 CONSOLE MESSAGE: line 55: [object DOMTokenList]
@@ skipping 44 matching lines @@
 console-format-collections.html:65 ArrayLike
 console-format-collections.html:66 ArrayLike
 console-format-collections.html:15 [select#sel, sel: select#sel]
 console-format-collections.html:19 (3) [script, script, script]
 console-format-collections.html:23 (2) [option, option, selectedIndex: 0]
 console-format-collections.html:27 (14) [html, head, script, script, script, body, p, div.c1.c2.c3, form#f, select#sel, option, option, input, input, f: form#f, sel: select#sel, x: NodeList(2)]
 console-format-collections.html:31 (3) [select#sel, input, input, sel: select#sel, x: RadioNodeList(2)]
 console-format-collections.html:35 (2) [input, input, value: ""]
 console-format-collections.html:41 (2) [1, Array(2)]
 console-format-collections.html:44 NonArrayWithLength {keys: Array(0)}
-console-format-collections.html:51 (2) [1, "2", callee: function, Symbol(Symbol.iterator): function]
+console-format-collections.html:51 (2) [1, "2", callee: ƒ, Symbol(Symbol.iterator): ƒ]
 console-format-collections.html:55 (3) ["c1", "c2", "c3", value: "c1 c2 c3"]
 console-format-collections.html:58 (5) [undefined × 5]
 console-format-collections.html:59 (4294967295) [undefined × 4294967295]
 console-format-collections.html:61 ArrayLike {length: -5}
 console-format-collections.html:62 ArrayLike {length: 5.6}
 console-format-collections.html:63 ArrayLike {length: NaN}
 console-format-collections.html:64 ArrayLike {length: Infinity}
 console-format-collections.html:65 ArrayLike {length: -0}
 console-format-collections.html:66 ArrayLike {length: 4294967296}