reduce diff churn due to server_mode test

reduce diff churn due to server_mode test
essentially verify the expected HTML in the test
this tripped on an interesting issue, we have two ways of computing MD5 hashes that produce different answers. I left that as a TODO.

R=jacobr@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/dd9ab2af960906485fb0df9de538bcd809d3f58e

[Jennifer Messerly, 2015-04-01 18:47:15]

jmesserly@google.com changed reviewers:
+ jacobr@google.com, sigmund@google.com

[Jacob, 2015-04-01 20:32:30]

lgtm

[Jennifer Messerly, 2015-04-01 20:49:14]

Committed patchset #1 (id:1) manually as
dd9ab2af960906485fb0df9de538bcd809d3f58e (presubmit successful).

[Siggi Cherem (dart-lang), 2015-04-01 21:28:20]

lgtm

https://codereview.chromium.org/1056613002/diff/1/test/codegen_test.dart
File test/codegen_test.dart (right):

https://codereview.chromium.org/1056613002/diff/1/test/codegen_test.dart#newc...
test/codegen_test.dart:272: if (dir.existsSync()) dir.deleteSync(recursive:
true);
minor nit: maybe just assert that it exists?

expect(dir.existsSync(), isTrue);
dir.deleteSync...