diff -r 000000000000 -r 6474c204b198 mobile/android/base/background/bagheera/BoundedByteArrayEntity.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/background/bagheera/BoundedByteArrayEntity.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,88 @@
+/* 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/. */
+
+package org.mozilla.gecko.background.bagheera;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import ch.boye.httpclientandroidlib.entity.AbstractHttpEntity;
+import ch.boye.httpclientandroidlib.entity.ByteArrayEntity;
+
+/**
+ * An entity that acts like {@link ByteArrayEntity}, but exposes a window onto
+ * the byte array that is a subsection of the array. The purpose of this is to
+ * allow a smaller entity to be created without having to resize the source
+ * array.
+ */
+public class BoundedByteArrayEntity extends AbstractHttpEntity implements
+    Cloneable {
+  protected final byte[] content;
+  protected final int    start;
+  protected final int    end;
+  protected final int    length;
+
+  /**
+   * Create a new entity that behaves exactly like a {@link ByteArrayEntity}
+   * created with a copy of <code>b</code> truncated to (
+   * <code>end - start</code>) bytes, starting at <code>start</code>.
+   *
+   * @param b the byte array to use.
+   * @param start the start index.
+   * @param end the end index.
+   */
+  public BoundedByteArrayEntity(final byte[] b, final int start, final int end) {
+    if (b == null) {
+      throw new IllegalArgumentException("Source byte array may not be null.");
+    }
+
+    if (end < start ||
+        start < 0   ||
+        end   < 0   ||
+        start > b.length ||
+        end   > b.length) {
+      throw new IllegalArgumentException("Bounds out of range.");
+    }
+    this.content = b;
+    this.start = start;
+    this.end = end;
+    this.length = end - start;
+  }
+
+  @Override
+  public boolean isRepeatable() {
+    return true;
+  }
+
+  @Override
+  public long getContentLength() {
+    return this.length;
+  }
+
+  @Override
+  public InputStream getContent() {
+    return new ByteArrayInputStream(this.content, this.start, this.length);
+  }
+
+  @Override
+  public void writeTo(final OutputStream outstream) throws IOException {
+    if (outstream == null) {
+      throw new IllegalArgumentException("Output stream may not be null.");
+    }
+    outstream.write(this.content);
+    outstream.flush();
+  }
+
+  @Override
+  public boolean isStreaming() {
+    return false;
+  }
+
+  @Override
+  public Object clone() throws CloneNotSupportedException {
+    return super.clone();
+  }
+}
\ No newline at end of file