Improve DEFINE_STATIC_LOCAL()'s handling of Blink GCed objects.

third_party/WebKit/Source/platform/heap/HeapTest.cpp

Index: third_party/WebKit/Source/platform/heap/HeapTest.cpp
diff --git a/third_party/WebKit/Source/platform/heap/HeapTest.cpp b/third_party/WebKit/Source/platform/heap/HeapTest.cpp
index 301efe469efd2ddaf6d639c9269991f053275b20..72e5901b3e9dcc8c05fd1c47b18d832647915a42 100644
--- a/third_party/WebKit/Source/platform/heap/HeapTest.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapTest.cpp
@@ -6509,4 +6509,25 @@ TEST(HeapTest, TestPersistentHeapVectorWithUnusedSlots)
 #endif
 }
 
+TEST(HeapTest, TestStaticLocals)
+{
+    // Sanity check DEFINE_STATIC_LOCAL()s over heap allocated objects and collections.
+
+    DEFINE_STATIC_LOCAL(IntWrapper, intWrapper, (new IntWrapper(33)));
+    DEFINE_STATIC_LOCAL(PersistentHeapVector<Member<IntWrapper>>, persistentHeapVectorIntWrapper, ());
+    DEFINE_STATIC_LOCAL(HeapVector<Member<IntWrapper>>, heapVectorIntWrapper, (new HeapVector<Member<IntWrapper>>));
+
+    EXPECT_EQ(33, intWrapper.value());
+    EXPECT_EQ(0u, persistentHeapVectorIntWrapper.size());
+    EXPECT_EQ(0u, heapVectorIntWrapper.size());
+
+    persistentHeapVectorIntWrapper.append(&intWrapper);
+    heapVectorIntWrapper.append(&intWrapper);
+    EXPECT_EQ(1u, persistentHeapVectorIntWrapper.size());
+    EXPECT_EQ(1u, heapVectorIntWrapper.size());
+
+    EXPECT_EQ(persistentHeapVectorIntWrapper[0], heapVectorIntWrapper[0]);
+    EXPECT_EQ(33, heapVectorIntWrapper[0]->value());
+}
+
 } // namespace blink