Add Certificate Transparency logs auditing

components/certificate_transparency/observed_leaf.cc

Index: components/certificate_transparency/observed_leaf.cc
diff --git a/components/certificate_transparency/observed_leaf.cc b/components/certificate_transparency/observed_leaf.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ee010b6c2ad62cced99adace83062b25de4db79b
--- /dev/null
+++ b/components/certificate_transparency/observed_leaf.cc
@@ -0,0 +1,43 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/certificate_transparency/observed_leaf.h"
+
+#include "base/time/time.h"
+
+using net::ct::MerkleTreeLeaf;
+
+ObservedLeaf::ObservedLeaf(MerkleTreeLeaf&& leaf, const base::Time& observed_at)
+    : leaf_(leaf), observed_at_(observed_at) {}
+
+ObservedLeaf::ObservedLeaf(const ObservedLeaf& other) = default;
+
+ObservedLeaf::ObservedLeaf(ObservedLeaf&&) = default;
+
+ObservedLeaf::~ObservedLeaf() = default;
+
+void ObservedLeaf::SetLeafIndex(uint64_t index) {
+  // The leaf index may be set only once. Doing so more than once indicates
+  // a programming error where the index is fetched more than once for a given
+  // leaf.
+  CHECK(!leaf_index_);

[Ryan Sleevi, 2016/06/30 22:48:18]

Then programming errors should be met with DCHECK, generally.

[Eran Messeri, 2016/07/01 13:24:00]

Done.

+  leaf_index_ = index;
+}
+
+bool ObservedLeaf::HasLeafIndex() const {
+  return bool(leaf_index_);
+}
+
+uint64_t ObservedLeaf::GetLeafIndex() const {
+  CHECK(leaf_index_);
+  return leaf_index_.value();
+}
+
+const MerkleTreeLeaf& ObservedLeaf::GetLeaf() const {
+  return leaf_;
+}
+
+const base::Time& ObservedLeaf::ObservedAt() const {
+  return observed_at_;
+}