Fix a defect on a test runner for ppapi tests

ppapi/tests/test_case.h

 // 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.
 
 #ifndef PPAPI_TESTS_TEST_CASE_H_
 #define PPAPI_TESTS_TEST_CASE_H_
 
 #include <cmath>
 #include <limits>
 #include <map>
@@ skipping 169 matching lines @@
           test_to_run_(test_to_run),
           loop_(loop) {
     }
     const std::string& result() { return result_; }
     static void ThreadFunction(void* runner) {
       static_cast<ThreadedTestRunner<T>*>(runner)->Run();
     }
 
    private:
     void Run() {
-      PP_DCHECK(PP_OK == loop_.AttachToCurrentThread());
+      int32_t result = loop_.AttachToCurrentThread();
+      static_cast<void>(result); // result is not used in the RELEASE build.
+      PP_DCHECK(PP_OK == result);
       result_ = (test_case_->*test_to_run_)();
       // Now give the loop a chance to clean up.
       loop_.PostQuit(true /* should_destroy */);
       loop_.Run();
       // Tell the main thread to quit its nested message loop, now that the test
       // is complete.
       TestCase::QuitMainMessageLoop(instance_);
     }
 
     std::string result_;
@@ skipping 181 matching lines @@
 #define ASSERT_SUBTEST_SUCCESS(function) \
   do { \
     std::string result = (function); \
     if (!result.empty()) \
       return result; \
   } while (false)
 
 #define PASS() return std::string()
 
 #endif  // PPAPI_TESTS_TEST_CASE_H_