Add thread checks to NaClBrowser, and make it leaky

chrome/test/nacl/nacl_browsertest.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 <stdio.h>
 #if defined(OS_POSIX)
 #include <unistd.h>
 #elif defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 292 matching lines @@
     cmd.AppendArgPath(script);
     cmd.AppendArg(base::IntToString(debug_stub_port));
     cmd.AppendArg("continue");
     LOG(INFO) << cmd.GetCommandLineString();
     *test_process = base::LaunchProcess(cmd, base::LaunchOptions());
   }
 
   void RunWithTestDebugger(const base::FilePath::StringType& test_url) {
     base::Process test_script;
     std::unique_ptr<base::Environment> env(base::Environment::Create());
-    nacl::NaClBrowser::GetInstance()->SetGdbDebugStubPortListener(
+    nacl::NaClBrowser::SetGdbDebugStubPortListenerForTest(
         base::Bind(&NaClBrowserTestPnaclDebug::StartTestScript,
                    base::Unretained(this), &test_script));
     // Turn on debug stub logging.
     env->SetVar("NACLVERBOSITY", "1");
     RunLoadTest(test_url);
     env->UnSetVar("NACLVERBOSITY");
-    nacl::NaClBrowser::GetInstance()->ClearGdbDebugStubPortListener();
+    nacl::NaClBrowser::ClearGdbDebugStubPortListenerForTest();
     int exit_code;
     LOG(INFO) << "Waiting for script to exit (which waits for embed to die).";
     test_script.WaitForExit(&exit_code);
     EXPECT_EQ(0, exit_code);
   }
 };
 
 // Test with the NaCl debug flag turned on, but mask off every URL
 // so that nothing is actually debugged.
 class NaClBrowserTestPnaclDebugMasked : public NaClBrowserTestPnaclDebug {
@@ skipping 103 matching lines @@
 }
 
 // TODO(ncbray) support glibc and PNaCl
 // flaky: crbug.com/375894
 IN_PROC_BROWSER_TEST_F(NaClBrowserTestNewlibExtension, DISABLED_MimeHandler) {
   RunNaClIntegrationTest(FILE_PATH_LITERAL(
       "ppapi_extension_mime_handler.html"));
 }
 
 }  // namespace