Replicating LayoutDumpFlags across OOPIFs.

components/test_runner/tracked_dictionary.cc

Index: components/test_runner/tracked_dictionary.cc
diff --git a/components/test_runner/tracked_dictionary.cc b/components/test_runner/tracked_dictionary.cc
new file mode 100644
index 0000000000000000000000000000000000000000..890553afcbfd25891ed42930598fd58956e38256
--- /dev/null
+++ b/components/test_runner/tracked_dictionary.cc
@@ -0,0 +1,44 @@
+// 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/test_runner/tracked_dictionary.h"
+
+#include <utility>
+
+namespace test_runner {
+
+TrackedDictionary::TrackedDictionary() {}
+
+void TrackedDictionary::ResetChangeTracking() {
+  changed_values_.Clear();
+}
+
+void TrackedDictionary::ApplyUntrackedChanges(
+    const base::DictionaryValue& new_changes) {
+  current_values_.MergeDictionary(&new_changes);
+
+  for (base::DictionaryValue::Iterator it(new_changes); !it.IsAtEnd();
+       it.Advance()) {
+    changed_values_.Remove(it.key(), nullptr);
+  }
+}
+
+void TrackedDictionary::Set(const std::string& path,
+                            scoped_ptr<base::Value> new_value) {
+  // Is this truly a *new* value?
+  const base::Value* old_value;
+  if (current_values_.Get(path, &old_value)) {
+    if (base::Value::Equals(old_value, new_value.get()))
+      return;
+  }
+
+  changed_values_.Set(path, new_value->CreateDeepCopy());
+  current_values_.Set(path, std::move(new_value));
+}
+
+void TrackedDictionary::SetBoolean(const std::string& path, bool new_value) {
+  Set(path, make_scoped_ptr(new base::FundamentalValue(new_value)));
+}
+
+}  // namespace test_runner