Fix ppapi TwoWayTest so that it constructs a unique IPC::ChannelHandle.

ppapi/proxy/plugin_var_tracker_unittest.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 "ipc/ipc_test_sink.h"
 #include "ppapi/c/dev/ppp_class_deprecated.h"
 #include "ppapi/proxy/plugin_var_tracker.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppapi_proxy_test.h"
 #include "ppapi/proxy/proxy_object_var.h"
@@ skipping 139 matching lines @@
   EXPECT_EQ(0,
             var_tracker().GetTrackedWithNoReferenceCountForObject(plugin_var));
   EXPECT_EQ(0u, sink().message_count());
 
   // Now free via the refcount, this should delete it.
   var_tracker().ReleaseVar(plugin_var);
   EXPECT_EQ(-1, var_tracker().GetRefCountForObject(plugin_var));
   EXPECT_EQ(host_object.value.as_id, GetObjectIDForUniqueReleaseObject());
 }
 
-TEST_F(PluginVarTrackerTest, DISABLED_RecursiveTrackWithNoRef) {
+TEST_F(PluginVarTrackerTest, RecursiveTrackWithNoRef) {
   PP_Var host_object = MakeObject(12345);
 
   // Receive a tracked object twice.
   PP_Var plugin_var = var_tracker().TrackObjectWithNoReference(
       host_object, plugin_dispatcher());
   EXPECT_EQ(1,
             var_tracker().GetTrackedWithNoReferenceCountForObject(plugin_var));
   PP_Var plugin_var2 = var_tracker().TrackObjectWithNoReference(
       host_object, plugin_dispatcher());
   EXPECT_EQ(plugin_var.value.as_id, plugin_var2.value.as_id);
@@ skipping 65 matching lines @@
 
   // Release the plugin ref to the var. Since the instance is gone this should
   // call deallocate.
   object = NULL;
   var_tracker().ReleaseVar(plugin_var);
   EXPECT_EQ(1, deallocate_called);
 }
 
 }  // namespace proxy
 }  // namespace ppapi