Close shm in image data destructor

ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc

 // Copyright (c) 2012 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 "native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.h"
 
 #include <stdio.h>
 #include <string.h>
 #include <sys/mman.h>
 #include "srpcgen/ppb_rpc.h"
@@ skipping 125 matching lines @@
 
 PluginImageData::PluginImageData()
     : shm_fd_(-1),
       shm_size_(0),
       addr_(NULL) {
   memset(&desc_, 0, sizeof(desc_));
 }
 
 PluginImageData::~PluginImageData() {
   Unmap();
+  if (shm_fd_ != -1) {
+    close(shm_fd_);
+    shm_fd_ = -1;
+  }
 }
 
 bool PluginImageData::InitFromBrowserResource(PP_Resource resource) {
   nacl_abi_size_t desc_size = static_cast<nacl_abi_size_t>(sizeof(desc_));
   int32_t success = PP_FALSE;
 
   NaClSrpcError result =
       PpbImageDataRpcClient::PPB_ImageData_Describe(
           GetMainSrpcChannel(),
           resource,
@@ skipping 19 matching lines @@
 }
 
 void PluginImageData::Unmap() {
   if (addr_) {
     munmap(addr_, ceil64k(shm_size_));
     addr_ = NULL;
   }
 }
 
 }  // namespace ppapi_proxy