Apply WTF::ParamStorageTraits<> to CrossThreadTaskN.

Before this CL, a pointer to a GarbageCollected object is stored by RawPtr<T> or
T* in CrossThreadTaskN.  If a GC happened before the task is performed,
the object can be swept.

Applying ParamStorageTraits makes it CrossThreadPersistent<T>, and
we can safely use createCrossThreadTask() for GarbageCollected objects.

BUG=378192

Review URL: https://codereview.chromium.org/934963003

git-svn-id: svn://svn.chromium.org/blink/trunk@190638 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/core.gypi

@@ -3744,6 +3744,7 @@
             'css/parser/SizesCalcParserTest.cpp',
             'css/resolver/FontBuilderTest.cpp',
             'dom/ActiveDOMObjectTest.cpp',
+            'dom/CrossThreadTaskTest.cpp',
             'dom/DOMImplementationTest.cpp',
             'dom/DocumentMarkerControllerTest.cpp',
             'dom/DocumentTest.cpp',

third_party/WebKit/Source/core/dom/CrossThreadTaskTest.cpp

+// Copyright 2015 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/dom/CrossThreadTask.h"
+
+#include "platform/heap/Handle.h"
+#include <gtest/gtest.h>
+
+namespace blink {
+
+class GCObject : public GarbageCollectedFinalized<GCObject> {
+public:
+    static int s_counter;
+    GCObject() { ++s_counter; }
+    ~GCObject() { --s_counter; }
+    DEFINE_INLINE_TRACE() { }
+    void run(GCObject*) { }
+};
+
+int GCObject::s_counter = 0;
+
+static void functionWithGarbageCollected(GCObject*)
+{
+}
+
+static void functionWithExecutionContext(ExecutionContext*, GCObject*)
+{
+}
+
+class CrossThreadTaskTest : public testing::Test {
+protected:
+    void SetUp() override
+    {
+        GCObject::s_counter = 0;
+    }
+    void TearDown() override
+    {
+        Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+        ASSERT_EQ(0, GCObject::s_counter);
+    }
+};
+
+TEST_F(CrossThreadTaskTest, CreateForGarbageCollectedMethod)
+{
+    OwnPtr<ExecutionContextTask> task1 = createCrossThreadTask(&GCObject::run, new GCObject, new GCObject);
+    OwnPtr<ExecutionContextTask> task2 = createCrossThreadTask(&GCObject::run, RawPtr<GCObject>(new GCObject), RawPtr<GCObject>(new GCObject));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    EXPECT_EQ(4, GCObject::s_counter);
+}
+
+TEST_F(CrossThreadTaskTest, CreateForFunctionWithGarbageCollected)
+{
+    OwnPtr<ExecutionContextTask> task1 = createCrossThreadTask(&functionWithGarbageCollected, new GCObject);
+    OwnPtr<ExecutionContextTask> task2 = createCrossThreadTask(&functionWithGarbageCollected, RawPtr<GCObject>(new GCObject));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    EXPECT_EQ(2, GCObject::s_counter);
+}
+
+TEST_F(CrossThreadTaskTest, CreateForFunctionWithExecutionContext)
+{
+    OwnPtr<ExecutionContextTask> task1 = createCrossThreadTask(&functionWithExecutionContext, new GCObject);
+    OwnPtr<ExecutionContextTask> task2 = createCrossThreadTask(&functionWithExecutionContext, RawPtr<GCObject>(new GCObject));
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
+    EXPECT_EQ(2, GCObject::s_counter);
+}
+
+}