Delay client registration of MessagePort to MessagePortChannel

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

Index: third_party/WebKit/Source/core/dom/MessagePort.cpp
diff --git a/third_party/WebKit/Source/core/dom/MessagePort.cpp b/third_party/WebKit/Source/core/dom/MessagePort.cpp
index 92e9facdd5da448fbb0c1b20551f3e6de72fada8..567c32dc900b7d0b27fbc696a2d316dfc03b9059 100644
--- a/third_party/WebKit/Source/core/dom/MessagePort.cpp
+++ b/third_party/WebKit/Source/core/dom/MessagePort.cpp
@@ -62,7 +62,7 @@ MessagePort::MessagePort(ExecutionContext& executionContext)
 
 MessagePort::~MessagePort()
 {
-    close();
+    DCHECK(!m_started || !isEntangled());
     if (m_scriptStateForConversion)
         m_scriptStateForConversion->disposePerContextData();
 }
@@ -117,7 +117,7 @@ MessagePortArray* MessagePort::toMessagePortArray(ExecutionContext* context, con
 WebMessagePortChannelUniquePtr MessagePort::disentangle()
 {
     DCHECK(m_entangledChannel);
-    m_entangledChannel->setClient(0);
+    m_entangledChannel->setClient(nullptr);
     return std::move(m_entangledChannel);
 }
 
@@ -139,6 +139,7 @@ void MessagePort::start()
     if (m_started)
         return;
 
+    m_entangledChannel->setClient(this);
     m_started = true;
     messageAvailable();
 }
@@ -146,7 +147,7 @@ void MessagePort::start()
 void MessagePort::close()
 {
     if (isEntangled())
-        m_entangledChannel->setClient(0);
+        m_entangledChannel->setClient(nullptr);
     m_closed = true;
 }
 
@@ -157,7 +158,6 @@ void MessagePort::entangle(WebMessagePortChannelUniquePtr remote)
     DCHECK(getExecutionContext());
 
     m_entangledChannel = std::move(remote);
-    m_entangledChannel->setClient(this);
 }
 
 const AtomicString& MessagePort::interfaceName() const