Add thread checks to NaClBrowser, and make it leaky

chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc

Index: chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc
diff --git a/chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc b/chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc
index 2fc111a9334cfe1419aedd424b8ba4d8ca1095ab..c34a17878c0c452be34794ee659ac2a35d645de1 100644
--- a/chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc
+++ b/chrome/browser/nacl_host/test/gdb_debug_stub_browsertest.cc
@@ -54,14 +54,14 @@ void NaClGdbDebugStubTest::RunDebugStubTest(const std::string& nacl_module,
                                             const std::string& test_name) {
   base::Process test_script;
   std::unique_ptr<base::Environment> env(base::Environment::Create());
-  nacl::NaClBrowser::GetInstance()->SetGdbDebugStubPortListener(
-      base::Bind(&NaClGdbDebugStubTest::StartTestScript,
-                 base::Unretained(this), &test_script, test_name));
+  nacl::NaClBrowser::GetInstance()->SetGdbDebugStubPortListenerForTest(

[Wez, 2017/01/14 01:53:11]

bradnelson: These GetInstance() calls barf because we're on the main thread. We
could:

1. Update the test to PostTask them to the IO thread.
2. Make the GDB debug stub port listener APIs static, since they're just for
test, so their use on the wrong thread here is not really an issue.
3. Relax the thread check in GetInstance(). I'd prefer not to do that since new
regressions will just creep back in.

+      base::Bind(&NaClGdbDebugStubTest::StartTestScript, base::Unretained(this),
+                 &test_script, test_name));
   // Turn on debug stub logging.
   env->SetVar("NACLVERBOSITY", "1");
   RunTestViaHTTP(nacl_module);
   env->UnSetVar("NACLVERBOSITY");
-  nacl::NaClBrowser::GetInstance()->ClearGdbDebugStubPortListener();
+  nacl::NaClBrowser::GetInstance()->ClearGdbDebugStubPortListenerForTest();
   int exit_code;
   test_script.WaitForExit(&exit_code);
   EXPECT_EQ(0, exit_code);