Oilpan: Prepare to make ExecutionContext GarbageCollectedMixin.

Source/platform/heap/HeapTest.cpp

Index: Source/platform/heap/HeapTest.cpp
diff --git a/Source/platform/heap/HeapTest.cpp b/Source/platform/heap/HeapTest.cpp
index 5c93ea68e5a3d0207641dd5d8846a9288692f6cd..3a2fc82352eb5577309670aef54433018fc3fc6a 100644
--- a/Source/platform/heap/HeapTest.cpp
+++ b/Source/platform/heap/HeapTest.cpp
@@ -3978,4 +3978,24 @@ TEST(HeapTest, NeedsAdjustAndMark)
     EXPECT_FALSE(NeedsAdjustAndMark<const UseMixin>::value);
 }
 
+TEST(HeapTest, Bind)
+{
+    Closure closure = bind(&Bar::trace, Bar::create(), static_cast<Visitor*>(0));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    // The closure should have a persistent handle to the Bar.
+    EXPECT_EQ(1u, Bar::s_live);
+
+    Closure closure2 = bind(&Bar::trace, RawPtr<Bar>(Bar::create()), static_cast<Visitor*>(0));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    // The closure should have a persistent handle to the Bar.
+    EXPECT_EQ(2u, Bar::s_live);
+
+    UseMixin::s_traceCount = 0;
+    Mixin* mixin = UseMixin::create();
+    Closure mixinClosure = bind(&Mixin::trace, mixin, static_cast<Visitor*>(0));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    // The closure should have a persistent handle to the mixin.
+    EXPECT_EQ(1, UseMixin::s_traceCount);
+}
+
 } // WebCore namespace