Make sanitizer tests handle IE11, where tagName can't be clobbered

Make sanitizer tests handle IE11, where tagName can't be clobbered
BUG=
R=sra@google.com

Committed: https://github.com/dart-lang/sdk/commit/ee0a5db6a5a07cc84db95532357b11ad5552bcd1

[Alan Knight, 2015-05-26 23:20:52]

alanknight@google.com changed reviewers:
+ sra@google.com

[Alan Knight, 2015-05-26 23:20:53]

Mostly just changing the tests, but I felt like tagName was just getting caught
by accident as a byproduct of toString throwing, so put in an extra level of
paranoia around it.

[sra1, 2015-05-27 00:45:19]

lgtm

https://codereview.chromium.org/1148893004/diff/1/tools/dom/src/Validators.dart
File tools/dom/src/Validators.dart (right):

https://codereview.chromium.org/1148893004/diff/1/tools/dom/src/Validators.da...
tools/dom/src/Validators.dart:201: if (elementTagName !=
elementTagName.toString() {
1. Parse error - missing ')'.
2. A malicious toString could return 'this'.
3. With --trust-type-annotations or type inference, this could plausibly be
optimized to a null check or `false`.

If you are really checking for a String, use
   if (confuse(elementTagName) is !String) {
     corrupted = true;
   }

[Alan Knight, 2015-05-27 19:54:47]

https://codereview.chromium.org/1148893004/diff/1/tools/dom/src/Validators.dart
File tools/dom/src/Validators.dart (right):

https://codereview.chromium.org/1148893004/diff/1/tools/dom/src/Validators.da...
tools/dom/src/Validators.dart:201: if (elementTagName !=
elementTagName.toString() {
On 2015/05/27 00:45:18, sra1 wrote:
> 1. Parse error - missing ')'.
> 2. A malicious toString could return 'this'.
> 3. With --trust-type-annotations or type inference, this could plausibly be
> optimized to a null check or `false`.
> 
> If you are really checking for a String, use
>    if (confuse(elementTagName) is !String) {
>      corrupted = true;
>    }

OK, this doesn't seem worthwhile, took it out.

[Alan Knight, 2015-05-27 19:56:15]

Committed patchset #2 (id:20001) manually as
ee0a5db6a5a07cc84db95532357b11ad5552bcd1 (presubmit successful).