Update V8 to version 4.1.0.21

This is a cherry-pick of all commits up to and including the
4.1.0.21 cherry-pick in Chromium.

Original commit message:

Version 4.1.0.21 (cherry-pick)

Merged 206e9136bde0f2b5ae8cb77afbb1e7833e5bd412

Unlink pages from the space page list after evacuation.

BUG=430201
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/953813002

Cr-Commit-Position: refs/branch-heads/4.1@{#22}
Cr-Branched-From: 2e08d2a7aa9d65d269d8c57aba82eb38a8cb0a18-refs/heads/candidates@{#25353}

---

FPIIM-449

Change-Id: I8c23c7bbb70772b4858fe8a47b64fa97ee0d1f8c
diff --git a/test/unittests/compiler/graph-reducer-unittest.cc b/test/unittests/compiler/graph-reducer-unittest.cc
new file mode 100644
index 0000000..dbdd4bb
--- /dev/null
+++ b/test/unittests/compiler/graph-reducer-unittest.cc
@@ -0,0 +1,123 @@
+// Copyright 2014 the V8 project 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 "src/compiler/graph.h"
+#include "src/compiler/graph-reducer.h"
+#include "src/compiler/operator.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+using testing::_;
+using testing::DefaultValue;
+using testing::Return;
+using testing::Sequence;
+using testing::StrictMock;
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+struct TestOperator : public Operator {
+  TestOperator(Operator::Opcode opcode, Operator::Properties properties,
+               size_t value_in, size_t value_out)
+      : Operator(opcode, properties, "TestOp", value_in, 0, 0, value_out, 0,
+                 0) {}
+};
+
+
+namespace {
+
+TestOperator OP0(0, Operator::kNoWrite, 0, 1);
+TestOperator OP1(1, Operator::kNoProperties, 1, 1);
+
+
+struct MockReducer : public Reducer {
+  MOCK_METHOD1(Reduce, Reduction(Node*));
+};
+
+}  // namespace
+
+
+class GraphReducerTest : public TestWithZone {
+ public:
+  GraphReducerTest() : graph_(zone()) {}
+
+  static void SetUpTestCase() {
+    TestWithZone::SetUpTestCase();
+    DefaultValue<Reduction>::Set(Reducer::NoChange());
+  }
+
+  static void TearDownTestCase() {
+    DefaultValue<Reduction>::Clear();
+    TestWithZone::TearDownTestCase();
+  }
+
+ protected:
+  void ReduceNode(Node* node, Reducer* r) {
+    GraphReducer reducer(graph(), zone());
+    reducer.AddReducer(r);
+    reducer.ReduceNode(node);
+  }
+
+  void ReduceNode(Node* node, Reducer* r1, Reducer* r2) {
+    GraphReducer reducer(graph(), zone());
+    reducer.AddReducer(r1);
+    reducer.AddReducer(r2);
+    reducer.ReduceNode(node);
+  }
+
+  void ReduceNode(Node* node, Reducer* r1, Reducer* r2, Reducer* r3) {
+    GraphReducer reducer(graph(), zone());
+    reducer.AddReducer(r1);
+    reducer.AddReducer(r2);
+    reducer.AddReducer(r3);
+    reducer.ReduceNode(node);
+  }
+
+  Graph* graph() { return &graph_; }
+
+ private:
+  Graph graph_;
+};
+
+
+TEST_F(GraphReducerTest, NodeIsDeadAfterReplace) {
+  StrictMock<MockReducer> r;
+  Node* node0 = graph()->NewNode(&OP0);
+  Node* node1 = graph()->NewNode(&OP1, node0);
+  Node* node2 = graph()->NewNode(&OP1, node0);
+  EXPECT_CALL(r, Reduce(node0)).WillOnce(Return(Reducer::NoChange()));
+  EXPECT_CALL(r, Reduce(node1)).WillOnce(Return(Reducer::Replace(node2)));
+  ReduceNode(node1, &r);
+  EXPECT_FALSE(node0->IsDead());
+  EXPECT_TRUE(node1->IsDead());
+  EXPECT_FALSE(node2->IsDead());
+}
+
+
+TEST_F(GraphReducerTest, ReduceOnceForEveryReducer) {
+  StrictMock<MockReducer> r1, r2;
+  Node* node0 = graph()->NewNode(&OP0);
+  EXPECT_CALL(r1, Reduce(node0));
+  EXPECT_CALL(r2, Reduce(node0));
+  ReduceNode(node0, &r1, &r2);
+}
+
+
+TEST_F(GraphReducerTest, ReduceAgainAfterChanged) {
+  Sequence s1, s2, s3;
+  StrictMock<MockReducer> r1, r2, r3;
+  Node* node0 = graph()->NewNode(&OP0);
+  EXPECT_CALL(r1, Reduce(node0));
+  EXPECT_CALL(r2, Reduce(node0));
+  EXPECT_CALL(r3, Reduce(node0)).InSequence(s1, s2, s3).WillOnce(
+      Return(Reducer::Changed(node0)));
+  EXPECT_CALL(r1, Reduce(node0)).InSequence(s1);
+  EXPECT_CALL(r2, Reduce(node0)).InSequence(s2);
+  ReduceNode(node0, &r1, &r2, &r3);
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8