Rename net::ct::LogEntry to SignedEntryData and clarify the comment.

components/certificate_transparency/single_tree_tracker.cc

Index: components/certificate_transparency/single_tree_tracker.cc
diff --git a/components/certificate_transparency/single_tree_tracker.cc b/components/certificate_transparency/single_tree_tracker.cc
index f3d151e65b4d14373762e125b458640bd4feb90f..99fe13fc720e44f5d4a1c2ec317d4bccad1b7f9c 100644
--- a/components/certificate_transparency/single_tree_tracker.cc
+++ b/components/certificate_transparency/single_tree_tracker.cc
@@ -25,7 +25,6 @@
 #include "net/log/net_log.h"
 
 using net::SHA256HashValue;
-using net::ct::LogEntry;
 using net::ct::MerkleAuditProof;
 using net::ct::MerkleTreeLeaf;
 using net::ct::SignedCertificateTimestamp;
@@ -33,10 +32,6 @@ using net::ct::SignedTreeHead;
 
 // Overview of the process for auditing CT log entries
 //
-// A CT log entry, represented by net::ct::LogEntry, is made up of the
-// end-entity certificate and the Signed Certificate Timestamp associated with
-// it.
-//
 // In this file, obsered CT log entries are audited for inclusion in the CT log.
 // A pre-requirement for auditing a log entry is having a Signed Tree Head (STH)
 // from that log that is 24 hours (MMD period) after the timestamp in the SCT.