[oilpan]: Move DOMWindowCSS to the oilpan heap using transition types.

R=ager@chromium.org, erik.corry@gmail.com, haraken@chromium.org, oilpan-reviews@chromium.org, tkent@chromium.org, vegorov@chromium.org, zerny@chromium.org
BUG=341815

Review URL: https://codereview.chromium.org/214503002

git-svn-id: svn://svn.chromium.org/blink/trunk@170167 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/css/CSS.idl

@@ -29,7 +29,8 @@
 
 [
     NoInterfaceObject,
-    ImplementedAs=DOMWindowCSS
+    ImplementedAs=DOMWindowCSS,
+    WillBeGarbageCollected
 ] interface CSS {
     boolean supports(DOMString property, DOMString value);
     boolean supports(DOMString conditionText);

third_party/WebKit/Source/core/css/DOMWindowCSS.cpp

@@ -37,9 +37,9 @@
 
 namespace WebCore {
 
-PassRefPtr<DOMWindowCSS> DOMWindowCSS::create()
+PassRefPtrWillBeRawPtr<DOMWindowCSS> DOMWindowCSS::create()
 {
-    return adoptRef(new DOMWindowCSS());
+    return adoptRefWillBeNoop(new DOMWindowCSS());
 }
 
 static String valueWithoutImportant(const String& value)

third_party/WebKit/Source/core/css/DOMWindowCSS.h

@@ -30,19 +30,22 @@
 #ifndef DOMWindowCSS_h
 #define DOMWindowCSS_h
 
+#include "heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
-class DOMWindowCSS : public RefCounted<DOMWindowCSS> {
+class DOMWindowCSS : public RefCountedWillBeGarbageCollected<DOMWindowCSS> {
 public:
-    static PassRefPtr<DOMWindowCSS> create();
+    static PassRefPtrWillBeRawPtr<DOMWindowCSS> create();
 
     bool supports(const String& property, const String& value) const;
     bool supports(const String& conditionText) const;
 
+    void trace(Visitor*) { }
+
 private:
     DOMWindowCSS()
     {

third_party/WebKit/Source/core/frame/DOMWindow.cpp

@@ -1882,6 +1882,7 @@ void DOMWindow::trace(Visitor* visitor)
     visitor->trace(m_localStorage);
     visitor->trace(m_applicationCache);
     visitor->trace(m_performance);
+    visitor->trace(m_css);
 #if ENABLE(OILPAN)
     HeapSupplementable<DOMWindow>::trace(visitor);
 #endif

third_party/WebKit/Source/core/frame/DOMWindow.h

@@ -371,7 +371,7 @@ enum PageshowEventPersistence {
 
         mutable RefPtrWillBeMember<Performance> m_performance;
 
-        mutable RefPtr<DOMWindowCSS> m_css;
+        mutable RefPtrWillBeMember<DOMWindowCSS> m_css;
 
         RefPtr<DOMWindowEventQueue> m_eventQueue;
         RefPtr<SerializedScriptValue> m_pendingStateObject;