Oilpan: Replace EAGERLY_FINALIZE in EventTarget's hierarchy with pre-finalizers

third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp

Index: third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp
diff --git a/third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp b/third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp
index c0e197c3007356b2805fb443ed90d5fd2a446dea..0edcaa7ddb11f42bcd5231dd38ad5fa88a5d25de 100644
--- a/third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp
+++ b/third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp
@@ -54,6 +54,7 @@ MIDIAccess::MIDIAccess(PassOwnPtr<MIDIAccessor> accessor, bool sysexEnabled, con
     , m_sysexEnabled(sysexEnabled)
     , m_hasPendingActivity(false)
 {
+    ThreadState::current()->registerPreFinalizer(this);
     m_accessor->setClient(this);
     for (size_t i = 0; i < ports.size(); ++i) {
         const MIDIAccessInitializer::PortDescriptor& port = ports[i];
@@ -69,6 +70,11 @@ MIDIAccess::~MIDIAccess()
 {
 }
 
+void MIDIAccess::dispose()
+{
+    m_accessor.clear();
+}
+
 EventListener* MIDIAccess::onstatechange()
 {
     return getAttributeEventListener(EventTypeNames::statechange);