diff -r 000000000000 -r 6474c204b198 netwerk/base/src/ArrayBufferInputStream.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/base/src/ArrayBufferInputStream.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,119 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <algorithm>
+#include "ArrayBufferInputStream.h"
+#include "nsStreamUtils.h"
+#include "jsapi.h"
+#include "jsfriendapi.h"
+
+NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream, nsIInputStream);
+
+ArrayBufferInputStream::ArrayBufferInputStream()
+: mBuffer(nullptr)
+, mBufferLength(0)
+, mOffset(0)
+, mPos(0)
+, mClosed(false)
+{
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::SetData(JS::Handle<JS::Value> aBuffer,
+                                uint32_t aByteOffset,
+                                uint32_t aLength,
+                                JSContext* aCx)
+{
+  if (!aBuffer.isObject()) {
+    return NS_ERROR_FAILURE;
+  }
+  JS::RootedObject arrayBuffer(aCx, &aBuffer.toObject());
+  if (!JS_IsArrayBufferObject(arrayBuffer)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mArrayBuffer.construct(aCx, aBuffer);
+
+  uint32_t buflen = JS_GetArrayBufferByteLength(arrayBuffer);
+  mOffset = std::min(buflen, aByteOffset);
+  mBufferLength = std::min(buflen - mOffset, aLength);
+  mBuffer = JS_GetStableArrayBufferData(aCx, arrayBuffer);
+  if (!mBuffer) {
+      return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Close()
+{
+  mClosed = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Available(uint64_t* aCount)
+{
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+  *aCount = mBufferLength - mPos;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount, uint32_t *aReadCount)
+{
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void *closure,
+                                     uint32_t aCount, uint32_t *result)
+{
+  NS_ASSERTION(result, "null ptr");
+  NS_ASSERTION(mBufferLength >= mPos, "bad stream state");
+
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  uint32_t remaining = mBufferLength - mPos;
+  if (!mArrayBuffer.empty()) {
+    JSObject* buf = &mArrayBuffer.ref().get().toObject();
+    uint32_t byteLength = JS_GetArrayBufferByteLength(buf);
+    if (byteLength == 0 && remaining != 0) {
+      mClosed = true;
+      return NS_BASE_STREAM_CLOSED;
+    }
+  } else {
+    MOZ_ASSERT(remaining == 0, "stream inited incorrectly");
+  }
+
+  if (!remaining) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  if (aCount > remaining) {
+    aCount = remaining;
+  }
+  nsresult rv = writer(this, closure, (char*)(mBuffer + mOffset) + mPos,
+                       0, aCount, result);
+  if (NS_SUCCEEDED(rv)) {
+    NS_ASSERTION(*result <= aCount,
+                 "writer should not write more than we asked it to write");
+    mPos += *result;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::IsNonBlocking(bool *aNonBlocking)
+{
+  *aNonBlocking = true;
+  return NS_OK;
+}