Tweaks to PPB_VarArrayBuffer in preperation for taking out of Dev.

webkit/plugins/ppapi/host_array_buffer_var.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/plugins/ppapi/host_array_buffer_var.h"
 
 using ppapi::ArrayBufferVar;
 using WebKit::WebArrayBuffer;
 
 namespace webkit {
 namespace ppapi {
 
 HostArrayBufferVar::HostArrayBufferVar(uint32 size_in_bytes)
     : buffer_(WebArrayBuffer::create(size_in_bytes, 1 /* element_size */)) {
 }
 
 HostArrayBufferVar::HostArrayBufferVar(const WebArrayBuffer& buffer)
     : buffer_(buffer) {
 }
 
 HostArrayBufferVar::~HostArrayBufferVar() {
 }
 
 void* HostArrayBufferVar::Map() {
   return buffer_.data();
 }
 
+void HostArrayBufferVar::Unmap() {
+  // We do not used shared memory on the host side. Nothing to do.
+}
+
 uint32 HostArrayBufferVar::ByteLength() {
   return buffer_.byteLength();
 }
 
 }  // namespace ppapi
 }  // namespace webkit