Added Dartium changes onto 45.0.2454.104

Source/wtf/ArrayBuffer.h

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 26 matching lines @@
 class ArrayBuffer;
 class ArrayBufferView;
 
 class WTF_EXPORT ArrayBuffer : public RefCounted<ArrayBuffer> {
 public:
     static inline PassRefPtr<ArrayBuffer> create(unsigned numElements, unsigned elementByteSize);
     static inline PassRefPtr<ArrayBuffer> create(ArrayBuffer*);
     static inline PassRefPtr<ArrayBuffer> create(const void* source, unsigned byteLength);
     static inline PassRefPtr<ArrayBuffer> create(ArrayBufferContents&);
 
+    // Create an ArrayBuffer for an existing piece of memory with no copying.
+    // The ArrayBuffer does not take ownership of the passed-in memory and care
+    // must be taken to not deallocate the data before the ArrayBuffer has been
+    // deallocated.
+    //
+    // FIXME: This should be removed when pointers into the JS/Dart heap can
+    // can be passed directly.
+    static inline PassRefPtr<ArrayBuffer> createNoCopy(void* source, unsigned byteLength);
+
+    // Only for use by Uint8ClampedArray::createUninitialized and SharedBuffer::getAsArrayBuffer.
     static inline PassRefPtr<ArrayBuffer> createOrNull(unsigned numElements, unsigned elementByteSize);
 
     // Only for use by XMLHttpRequest::responseArrayBuffer and Internals::serializeObject
     // (through DOMArrayBuffer::createUninitialized).
     static inline PassRefPtr<ArrayBuffer> createUninitialized(unsigned numElements, unsigned elementByteSize);
 
     static inline PassRefPtr<ArrayBuffer> createShared(unsigned numElements, unsigned elementByteSize);
     static inline PassRefPtr<ArrayBuffer> createShared(const void* source, unsigned byteLength);
 
     inline void* data();
@@ skipping 56 matching lines @@
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(const void* source, unsigned byteLength)
 {
     ArrayBufferContents contents(byteLength, 1, ArrayBufferContents::NotShared, ArrayBufferContents::ZeroInitialize);
     RELEASE_ASSERT(contents.data());
     RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(contents));
     memcpy(buffer->data(), source, byteLength);
     return buffer.release();
 }
 
+PassRefPtr<ArrayBuffer> ArrayBuffer::createNoCopy(void* source, unsigned byteLength)
+{
+    // FIXME: What do we pass in for a DeallocationObserver?
+    ArrayBufferContents contents(source, byteLength, ArrayBufferContents::SharingType::NotShared);
+    return adoptRef(new ArrayBuffer(contents));
+}
+
 PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBufferContents& contents)
 {
     RELEASE_ASSERT(contents.data());
     return adoptRef(new ArrayBuffer(contents));
 }
 
 PassRefPtr<ArrayBuffer> ArrayBuffer::createOrNull(unsigned numElements, unsigned elementByteSize)
 {
     return createOrNull(numElements, elementByteSize, ArrayBufferContents::ZeroInitialize);
 }
@@ skipping 35 matching lines @@
 PassRefPtr<ArrayBuffer> ArrayBuffer::createShared(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
 {
     ArrayBufferContents contents(numElements, elementByteSize, ArrayBufferContents::Shared, policy);
     RELEASE_ASSERT(contents.data());
     return adoptRef(new ArrayBuffer(contents));
 }
 
 ArrayBuffer::ArrayBuffer(ArrayBufferContents& contents)
     : m_firstView(0), m_isNeutered(false)
 {
-    contents.transfer(m_contents);
+    if (contents.isShared())
+        contents.shareWith(m_contents);
+    else
+        contents.transfer(m_contents);
 }
 
 void* ArrayBuffer::data()
 {
     return m_contents.data();
 }
 
 const void* ArrayBuffer::data() const
 {
     return m_contents.data();
@@ skipping 26 matching lines @@
     if (index < 0)
         index = currentLength + index;
     return clampValue(index, 0, currentLength);
 }
 
 } // namespace WTF
 
 using WTF::ArrayBuffer;
 
 #endif // ArrayBuffer_h