PPAPI: Purposely leak ProxyLock, fix shutdown race

ppapi/shared_impl/var_value_conversions_unittest.cc

 // Copyright (c) 2013 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 "ppapi/shared_impl/var_value_conversions.h"
 
 #include <cmath>
 #include <cstring>
 
 #include "base/logging.h"
@@ skipping 124 matching lines @@
 
 class VarValueConversionsTest : public testing::Test {
  public:
   VarValueConversionsTest() {
   }
   virtual ~VarValueConversionsTest() {
   }
 
   // testing::Test implementation.
   virtual void SetUp() {
+    ProxyLock::EnableLockingOnThreadForTest();
     ProxyLock::Acquire();
   }
   virtual void TearDown() {
     ASSERT_TRUE(PpapiGlobals::Get()->GetVarTracker()->GetLiveVars().empty());
     ProxyLock::Release();
   }
 
  private:
   TestGlobals globals_;
 };
@@ skipping 231 matching lines @@
       const base::Value* value = NULL;
       ASSERT_TRUE(list_value.Get(i, &value));
       ASSERT_TRUE(Equals(*value, vars[i]));
 
       PpapiGlobals::Get()->GetVarTracker()->ReleaseVar(vars[i]);
     }
   }
 }
 
 }  // namespace ppapi