[oilpan]: Fix webkit unit tests for oilpan.

Source/web/tests/WebViewTest.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1791 matching lines @@
 // This test checks that deleting nodes which have only non-JS-registered touch
 // handlers also removes them from the event handler registry. Note that this
 // is different from detaching and re-attaching the same node, which is covered
 // by layout tests under fast/events/.
 TEST_F(WebViewTest, DeleteElementWithRegisteredHandler)
 {
     std::string url = m_baseURL + "simple_div.html";
     URLTestHelpers::registerMockedURLLoad(toKURL(url), "simple_div.html");
     WebViewImpl* webViewImpl = m_webViewHelper.initializeAndLoad(url, true);
 
-    WebCore::Document* document = webViewImpl->mainFrameImpl()->frame()->document();
+    RefPtrWillBePersistent<WebCore::Document> document = webViewImpl->mainFrameImpl()->frame()->document();
     WebCore::Element* div = document->getElementById("div");
     WebCore::EventHandlerRegistry& registry = document->frameHost()->eventHandlerRegistry();
 
     registry.didAddEventHandler(*div, WebCore::EventHandlerRegistry::ScrollEvent);
     EXPECT_TRUE(registry.hasEventHandlers(WebCore::EventHandlerRegistry::ScrollEvent));
 
     WebCore::TrackExceptionState exceptionState;
     div->remove(exceptionState);
+#if ENABLE(OILPAN)
+    // For oilpan we have to force a GC to ensure the event handlers have been removed when
+    // checking below. We do a precise GC (collectAllGarbage does not scan the stack)
+    // to ensure the div element dies. This is also why the Document is in a Persistent
+    // since we want that to stay around.
+    Heap::collectAllGarbage();
+#endif
     EXPECT_FALSE(registry.hasEventHandlers(WebCore::EventHandlerRegistry::ScrollEvent));
 }
 
 static WebRect ExpectedRootBounds(WebCore::Document* document, float scaleFactor)
 {
     WebCore::Element* element = document->getElementById("root");
     if (!element)
         element = document->getElementById("target");
     if (element->hasTagName(WebCore::HTMLNames::iframeTag))
         return ExpectedRootBounds(toHTMLIFrameElement(element)->contentDocument(), scaleFactor);
@@ skipping 268 matching lines @@
 
     EXPECT_EQ(0, client.getUserGestureNotificationsCount());
 
     EXPECT_TRUE(tapElementById(webView, WebInputEvent::GestureTap, WebString::fromUTF8("target")));
 
     EXPECT_EQ(1, client.getUserGestureNotificationsCount());
     webView->setAutofillClient(0);
 }
 
 } // namespace