Rename references to "external pages" as "snapshot pages" to avoid confusion with the kind of exter…

runtime/vm/virtual_memory_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_FUCHSIA)
 
 #include "vm/virtual_memory.h"
 
 #include <magenta/status.h>
@@ skipping 153 matching lines @@
             mx_status_get_string(status));
     return NULL;
   }
   VmarList::AddVmar(vmar, addr, size);
   MemoryRegion region(reinterpret_cast<void*>(addr), size);
   return new VirtualMemory(region, vmar);
 }
 
 
 VirtualMemory::~VirtualMemory() {
-  if (!embedder_allocated()) {
+  if (vm_owns_region()) {
     mx_handle_t vmar = static_cast<mx_handle_t>(handle());
     mx_status_t status = mx_vmar_destroy(vmar);
     if (status != NO_ERROR) {
       LOG_ERR("mx_vmar_destroy failed: %s\n", mx_status_get_string(status));
     }
     status = mx_handle_close(vmar);
     if (status != NO_ERROR) {
       LOG_ERR("mx_handle_close failed: %s\n", mx_status_get_string(status));
     }
     VmarList::RemoveVmar(start());
@@ skipping 88 matching lines @@
     return false;
   }
   LOG_INFO("mx_vmar_protect(%lx, %lx, %x) success\n", page_address,
            end_address - page_address, prot);
   return true;
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_FUCHSIA)