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..21eafab9d65bc3465a270e27e2043dd9c6b16a67 100644
--- a/Source/wtf/ArrayBuffer.cpp
+++ b/Source/wtf/ArrayBuffer.cpp
@@ -33,10 +33,11 @@ namespace WTF {
 
 bool ArrayBuffer::transfer(ArrayBufferContents& result)
 {
+    ASSERT(!isShared());
     RefPtr<ArrayBuffer> keepAlive(this);
 
     if (!m_contents.data()) {
-        result.clear();
+        result.neuter();
         return false;
     }
 
@@ -66,6 +67,20 @@ bool ArrayBuffer::transfer(ArrayBufferContents& result)
     return true;
 }
 
+bool ArrayBuffer::shareContentsWith(ArrayBufferContents& result)
+{
+    ASSERT(isShared());
+    RefPtr<ArrayBuffer> keepAlive(this);
+
+    if (!m_contents.data()) {
+        result.neuter();
+        return false;
+    }
+
+    m_contents.shareWith(result);
+    return true;
+}
+
 void ArrayBuffer::addView(ArrayBufferView* view)
 {
     view->m_buffer = this;