Add a ref-counted data holder to ArrayBufferContents

Source/wtf/ArrayBuffer.cpp

Index: Source/wtf/ArrayBuffer.cpp
diff --git a/Source/wtf/ArrayBuffer.cpp b/Source/wtf/ArrayBuffer.cpp
index cfbdc9de1418bca9204a2a7a94e37116d28251ac..a0b89d0a2abbf358cada1f847262a00e1016f48d 100644
--- a/Source/wtf/ArrayBuffer.cpp
+++ b/Source/wtf/ArrayBuffer.cpp
@@ -36,10 +36,17 @@ bool ArrayBuffer::transfer(ArrayBufferContents& result)
     RefPtr<ArrayBuffer> keepAlive(this);
 
     if (!m_contents.data()) {
-        result.clear();
+        result.neuter();
         return false;
     }
 
+    if (isShared()) {
+        m_contents.transfer(result);
+        // Return early to prevent neutering views when transferring
+        // SharedArrayBuffers.
+        return true;
+    }
+
     bool allViewsAreNeuterable = true;
     for (ArrayBufferView* i = m_firstView; i; i = i->m_nextView) {
         if (!i->isNeuterable())
@@ -48,6 +55,7 @@ bool ArrayBuffer::transfer(ArrayBufferContents& result)
 
     if (allViewsAreNeuterable) {
         m_contents.transfer(result);
+        m_contents.neuter();
     } else {
         m_contents.copyTo(result);
         if (!result.data())