Work around a Purify bug by making an object used by NetTestSuite stack alloc...

net/base/host_resolver_unittest.h

 // Copyright (c) 2006-2009 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.
 
 #ifndef NET_BASE_HOST_RESOLVER_UNITTEST_H_
 #define NET_BASE_HOST_RESOLVER_UNITTEST_H_
 
 #ifdef UNIT_TEST
 
 #include <list>
@@ skipping 107 matching lines @@
 // to the previously set HostMapper (see SetHostMapper). This is true for all
 // mappers defined in this file. If no HostMapper matches a given hostname, then
 // the hostname will be unmodified.
 class ScopedHostMapper {
  public:
   ScopedHostMapper(HostMapper* mapper) : current_host_mapper_(mapper) {
     previous_host_mapper_ = SetHostMapper(current_host_mapper_.get());
     current_host_mapper_->set_previous_mapper(previous_host_mapper_.get());
   }
 
+  ScopedHostMapper() {}
+
   ~ScopedHostMapper() {
     HostMapper* old_mapper = SetHostMapper(previous_host_mapper_.get());
     // The lifetimes of multiple instances must be nested.
     CHECK(old_mapper == current_host_mapper_.get());
   }
 
+  void Init(HostMapper* mapper) {
+    current_host_mapper_ = mapper;
+    previous_host_mapper_ = SetHostMapper(current_host_mapper_.get());
+    current_host_mapper_->set_previous_mapper(previous_host_mapper_.get());
+  }
+
  private:
   scoped_refptr<HostMapper> current_host_mapper_;
   scoped_refptr<HostMapper> previous_host_mapper_;
 };
 
 }  // namespace net
 
 #endif  // UNIT_TEST
 
 #endif  // NET_BASE_HOST_RESOLVER_UNITTEST_H_