Add support for MD2, MD4, and MD5 to SignatureAlgorithm.

Add support for MD2, MD4, and MD5 to SignatureAlgorithm.

(At a parsing level it is useful to recognize these for error handling,
even if in practice they aren't used when verifying signatures.)

Review-Url: https://codereview.chromium.org/2728953003
Cr-Commit-Position: refs/heads/master@{#455350}
(cherry picked from commit 37e84a0d658536248f4a4372551c36db2e614c1f)

BUG=690821
Review-Url: https://codereview.chromium.org/2750703002 .
Cr-Commit-Position: refs/branch-heads/3029@{#165}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/37ff2437dc0a3c4c0e6cf0976b1967bca2d5f057

[eroman, 2017-03-13 21:23:06]

Description was changed from

==========
Add support for MD2, MD4, and MD5 to SignatureAlgorithm.

(At a parsing level it is useful to recognize these for error handling,
even if in practice they aren't used when verifying signatures.)

Review-Url: https://codereview.chromium.org/2728953003
Cr-Commit-Position: refs/heads/master@{#455350}
(cherry picked from commit 37e84a0d658536248f4a4372551c36db2e614c1f)

BUG=690821
==========

to

==========
Add support for MD2, MD4, and MD5 to SignatureAlgorithm.

(At a parsing level it is useful to recognize these for error handling,
even if in practice they aren't used when verifying signatures.)

Review-Url: https://codereview.chromium.org/2728953003
Cr-Commit-Position: refs/heads/master@{#455350}
(cherry picked from commit 37e84a0d658536248f4a4372551c36db2e614c1f)

BUG=690821

Review-Url: https://codereview.chromium.org/2750703002 .
Cr-Commit-Position: refs/branch-heads/3029@{#165}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/37ff2437dc0a3c4c0e6cf0976b19...
==========

[eroman, 2017-03-13 21:23:08]

Committed patchset #1 (id:1) manually as
37ff2437dc0a3c4c0e6cf0976b1967bca2d5f057.