[Sync] Fix modification-while-iterating bug in extensions integration tests

chrome/test/live_sync/live_extensions_sync_test_base.cc

 // Copyright (c) 2010 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 "chrome/test/live_sync/live_extensions_sync_test_base.h"
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 93 matching lines @@
   CHECK(profile);
   CHECK(extension.get());
   profile->GetExtensionsService()->OnExtensionInstalled(extension, true);
 }
 
 void LiveExtensionsSyncTestBase::InstallAllPendingExtensions(
     Profile* profile) {
   // TODO(akalin): Mock out the servers that the extensions
   // auto-update mechanism talk to so as to more closely match what
   // actually happens.
-  const PendingExtensionMap& pending_extensions =
+
+  // We make a copy here since InstallExtension() removes the
+  // extension from the extensions service's copy.
+  PendingExtensionMap pending_extensions =
       profile->GetExtensionsService()->pending_extensions();
   for (PendingExtensionMap::const_iterator it = pending_extensions.begin();
        it != pending_extensions.end(); ++it) {
     ExtensionIdMap::const_iterator it2 = extensions_by_id_.find(it->first);
     CHECK(it2 != extensions_by_id_.end());
     InstallExtension(profile, it2->second);
   }
 }