Add parsing code for TBSCertificate's "validity" field.

net/data/parse_certificate_unittest/tbs_v3_extensions.pem

Index: net/data/parse_certificate_unittest/tbs_v3_extensions.pem
diff --git a/net/data/parse_certificate_unittest/tbs_v3_extensions.pem b/net/data/parse_certificate_unittest/tbs_v3_extensions.pem
index d8bd8bcf13158637628500cc455eb44365ce9d93..c8a59aa2d5a8ecb005d8d749b48429fac91f24bc 100644
--- a/net/data/parse_certificate_unittest/tbs_v3_extensions.pem
+++ b/net/data/parse_certificate_unittest/tbs_v3_extensions.pem
@@ -1,16 +1,15 @@
 This is a very basic TBSCertificate. It is valid from the perspective of
 ParseTbsCertificate(), however its sub-fields are mainly bogus. This
-TBSCertificate contains no optional fields (no issuerUniqueID, subjectUniqueID,
-extensions)
-
+TBSCertificate contains extensions.
 
 
 -----BEGIN TBS CERTIFICATE-----
-MCigAwIBAgIBATADBAEBMAMEAQUwAwQBCDADBAEKMAMEAfOjBTADBAHd
+MEOgAwIBAgIBATADBAEBMAMEAQUwHhcNMTIxMDE4MDMxMjAwWhcNMTMxMDE4MTQ1OTU5WjADBAG
+DMAMEAfOjBTADBAHd
 -----END TBS CERTIFICATE-----
 
 $ openssl asn1parse -i < [TBS CERTIFICATE]
-    0:d=0  hl=2 l=  40 cons: SEQUENCE          
+    0:d=0  hl=2 l=  67 cons: SEQUENCE          
     2:d=1  hl=2 l=   3 cons:  cont [ 0 ]        
     4:d=2  hl=2 l=   1 prim:   INTEGER           :02
     7:d=1  hl=2 l=   1 prim:  INTEGER           :01
@@ -18,16 +17,16 @@ $ openssl asn1parse -i < [TBS CERTIFICATE]
    12:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:01
    15:d=1  hl=2 l=   3 cons:  SEQUENCE          
    17:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:05
-   20:d=1  hl=2 l=   3 cons:  SEQUENCE          
-   22:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:08
-   25:d=1  hl=2 l=   3 cons:  SEQUENCE          
-   27:d=2  hl=2 l=   1 prim:   OCTET STRING      :
-
-   30:d=1  hl=2 l=   3 cons:  SEQUENCE          
-   32:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:F3
-   35:d=1  hl=2 l=   5 cons:  cont [ 3 ]        
-   37:d=2  hl=2 l=   3 cons:   SEQUENCE          
-   39:d=3  hl=2 l=   1 prim:    OCTET STRING      [HEX DUMP]:DD
+   20:d=1  hl=2 l=  30 cons:  SEQUENCE          
+   22:d=2  hl=2 l=  13 prim:   UTCTIME           :121018031200Z
+   37:d=2  hl=2 l=  13 prim:   UTCTIME           :131018145959Z
+   52:d=1  hl=2 l=   3 cons:  SEQUENCE          
+   54:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:83
+   57:d=1  hl=2 l=   3 cons:  SEQUENCE          
+   59:d=2  hl=2 l=   1 prim:   OCTET STRING      [HEX DUMP]:F3
+   62:d=1  hl=2 l=   5 cons:  cont [ 3 ]        
+   64:d=2  hl=2 l=   3 cons:   SEQUENCE          
+   66:d=3  hl=2 l=   1 prim:    OCTET STRING      [HEX DUMP]:DD
 
 
 
@@ -57,23 +56,31 @@ $ openssl asn1parse -i < [ISSUER]
 
 
 
------BEGIN VALIDITY-----
-MAMEAQg=
------END VALIDITY-----
+-----BEGIN VALIDITY NOTBEFORE-----
+eWVhcj0yMDEyLCBtb250aD0xMCwgZGF5PTE4LCBob3Vycz0zLCBtaW51dGVzPTEyLCBzZWNvbmR
+zPTA=
+-----END VALIDITY NOTBEFORE-----
 
-$ openssl asn1parse -i < [VALIDITY]
-    0:d=0  hl=2 l=   3 cons: SEQUENCE          
-    2:d=1  hl=2 l=   1 prim:  OCTET STRING      [HEX DUMP]:08
+VALIDITY NOTBEFORE: year=2012, month=10, day=18, hours=3, minutes=12, seconds=0
+
+
+
+-----BEGIN VALIDITY NOTAFTER-----
+eWVhcj0yMDEzLCBtb250aD0xMCwgZGF5PTE4LCBob3Vycz0xNCwgbWludXRlcz01OSwgc2Vjb25
+kcz01OQ==
+-----END VALIDITY NOTAFTER-----
+
+VALIDITY NOTAFTER: year=2013, month=10, day=18, hours=14, minutes=59, seconds=59
 
 
 
 -----BEGIN SUBJECT-----
-MAMEAQo=
+MAMEAYM=
 -----END SUBJECT-----
 
 $ openssl asn1parse -i < [SUBJECT]
     0:d=0  hl=2 l=   3 cons: SEQUENCE          
-    2:d=1  hl=2 l=   1 prim:  OCTET STRING      :
+    2:d=1  hl=2 l=   1 prim:  OCTET STRING      [HEX DUMP]:83