Free HashSets on setWholeSubtreeInvalid.

Source/core/css/analyzer/DescendantInvalidationSetTest.cpp

Index: Source/core/css/analyzer/DescendantInvalidationSetTest.cpp
diff --git a/Source/core/css/analyzer/DescendantInvalidationSetTest.cpp b/Source/core/css/analyzer/DescendantInvalidationSetTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..fb2e480988cfcdc924cc2779111f521d49799ba1
--- /dev/null
+++ b/Source/core/css/analyzer/DescendantInvalidationSetTest.cpp
@@ -0,0 +1,76 @@
+// Copyright 2014 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 "config.h"
+#include "core/css/analyzer/DescendantInvalidationSet.h"
+
+#include <gtest/gtest.h>
+
+using namespace WebCore;
+
+namespace {
+
+// Once we setWholeSubtreeInvalid, we should not keep the HashSets.
+TEST(DescendantInvalidationSetTest, SubtreeInvalid_AddBefore)
+{
+    RefPtr<DescendantInvalidationSet> set = DescendantInvalidationSet::create();
+    set->addClass("a");
+    set->setWholeSubtreeInvalid();
+
+    Vector<AtomicString> classes;
+    set->getClasses(classes);
+
+    ASSERT_TRUE(classes.isEmpty());
+}
+
+// Don't (re)create HashSets if we've already setWholeSubtreeInvalid.
+TEST(DescendantInvalidationSetTest, SubtreeInvalid_AddAfter)
+{
+    RefPtr<DescendantInvalidationSet> set = DescendantInvalidationSet::create();
+    set->setWholeSubtreeInvalid();
+    set->addClass("a");
+
+    Vector<AtomicString> classes;
+    set->getClasses(classes);
+
+    ASSERT_TRUE(classes.isEmpty());
+}
+
+// No need to keep the HashSets when combining with a wholeSubtreeInvalid set.
+TEST(DescendantInvalidationSetTest, SubtreeInvalid_Combine_1)
+{
+    RefPtr<DescendantInvalidationSet> set1 = DescendantInvalidationSet::create();
+    RefPtr<DescendantInvalidationSet> set2 = DescendantInvalidationSet::create();
+
+    set1->addClass("a");
+    set2->setWholeSubtreeInvalid();
+
+    set1->combine(*set2);
+
+    Vector<AtomicString> classes;
+    set1->getClasses(classes);
+
+    ASSERT_TRUE(set1->wholeSubtreeInvalid());
+    ASSERT_TRUE(classes.isEmpty());
+}
+
+// No need to add HashSets from combining set when we already have wholeSubtreeInvalid.
+TEST(DescendantInvalidationSetTest, SubtreeInvalid_Combine_2)
+{
+    RefPtr<DescendantInvalidationSet> set1 = DescendantInvalidationSet::create();
+    RefPtr<DescendantInvalidationSet> set2 = DescendantInvalidationSet::create();
+
+    set1->setWholeSubtreeInvalid();
+    set2->addClass("a");
+
+    set1->combine(*set2);
+
+    Vector<AtomicString> classes;
+    set1->getClasses(classes);
+
+    ASSERT_TRUE(set1->wholeSubtreeInvalid());
+    ASSERT_TRUE(classes.isEmpty());
+}
+
+} // namespace