[ledger] Fix logs and comments on object digests.

Test: everything still builds
Change-Id: I72c679110c0233aac7761fe8e03d83f81edeeb4c
diff --git a/bin/ledger/storage/fake/fake_commit.cc b/bin/ledger/storage/fake/fake_commit.cc
index b5912f6..26b2c1c 100644
--- a/bin/ledger/storage/fake/fake_commit.cc
+++ b/bin/ledger/storage/fake/fake_commit.cc
@@ -34,7 +34,7 @@
 uint64_t FakeCommit::GetGeneration() const { return journal_->GetGeneration(); }
 
 ObjectIdentifier FakeCommit::GetRootIdentifier() const {
-  // The object digest fake here: using journal id is arbitrary.
+  // The object digest is fake here: using journal id is arbitrary.
   return encryption::MakeDefaultObjectIdentifier(
       ObjectDigest(journal_->GetId()));
 }
diff --git a/bin/ledger/storage/impl/page_storage_impl.h b/bin/ledger/storage/impl/page_storage_impl.h
index 149ca87..141288b 100644
--- a/bin/ledger/storage/impl/page_storage_impl.h
+++ b/bin/ledger/storage/impl/page_storage_impl.h
@@ -161,9 +161,8 @@
 
   bool IsFirstCommit(CommitIdView id);
 
-  // Adds the given synced object. |object_identifier| will be validated against
-  // the expected one based on the |data| and an |OBJECT_DIGEST_MISSMATCH| error
-  // will be returned in case of missmatch.
+  // Adds the given synced object. |object_identifier| is expected to match the
+  // given |data|.
   void AddPiece(ObjectIdentifier object_identifier, ChangeSource source,
                 IsObjectSynced is_object_synced,
                 std::unique_ptr<DataSource::DataChunk> data,
diff --git a/bin/ledger/storage/impl/page_storage_unittest.cc b/bin/ledger/storage/impl/page_storage_unittest.cc
index f83c8fa..e5e7731 100644
--- a/bin/ledger/storage/impl/page_storage_unittest.cc
+++ b/bin/ledger/storage/impl/page_storage_unittest.cc
@@ -519,11 +519,11 @@
 
     if (!called) {
       return ::testing::AssertionFailure()
-             << "TreeNode::FromDigest callback was not executed.";
+             << "TreeNode::FromIdentifier callback was not executed.";
     }
     if (status != Status::OK) {
       return ::testing::AssertionFailure()
-             << "TreeNode::FromDigest failed with status " << status;
+             << "TreeNode::FromIdentifier failed with status " << status;
     }
     node->swap(result);
     return ::testing::AssertionSuccess();