[Autofill] Update the autocomplete types implementation to match the current HTML spec.

chrome/test/data/autofill/heuristics/input/01_autocomplete_attribute_advanced.html

+<!-- Whitespace should be trimmed; case should be normalized. -->
+<form action="autocompletetype.html" method="post">
+  <input id="1.n" autocomplete="  NAME "><br>
+  <input id="1.e" autocomplete=" WoRk eMaIl"><br>
+  <input id="1.a" autocomplete=" SECTION-one SHIPping street-address"><br>

[Dan Beam, 2012/10/19 00:12:44]

nit: trimmable space at end

[Ilya Sherman, 2012/10/19 04:19:32]

Done.  (Made it a tab, even!)

+</form>
+
+<!-- The presence of at least one type hint should disable all other forms of
+     heuristics. -->
+<form action="autocompletetype.html" method="post">
+  <input id="2.name"><br>
+  <input id="2.email"><br>
+  <input id="2.t" autocomplete="tel"><br>
+  <input id="2.address"><br>
+</form>
+
+<!-- This is true even if the attribute value is invalid. -->
+<form action="autocompletetype.html" method="post">
+  <input id="3.name"><br>
+  <input id="3.email"><br>
+  <input id="3.o" autocomplete="other"><br>
+  <input id="3.address"><br>
+</form>
+
+<!-- But special values like "on" or "off" should have no effect. -->
+<form action="autocompletetype.html" method="post">
+  <input id="4.phone"><br>
+  <input id="4.email"><br>
+  <input id="4.a" autocomplete="on"><br>
+  <input id="4.b" autocomplete="oFf "><br>
+  <input id="4.c" autocomplete=""><br>
+  <input id="4.city"><br>
+</form>