Modify ThreadChecker and NonThreadSafe so that their functionality is

base/threading/thread_checker.cc

Index: base/threading/thread_checker.cc
diff --git a/base/threading/thread_checker.cc b/base/threading/thread_checker.cc
index 28ba400844549ba777a0f33c87a5305e46560e9e..da61384f3ffd3ca7e3532a500f65cb85aa6e3001 100644
--- a/base/threading/thread_checker.cc
+++ b/base/threading/thread_checker.cc
@@ -4,29 +4,27 @@
 
 #include "base/threading/thread_checker.h"
 
-// This code is only done in debug builds.
-#ifndef NDEBUG
-
 namespace base {
 
-ThreadChecker::ThreadChecker() : valid_thread_id_(kInvalidThreadId) {
+ThreadCheckerImpl::ThreadCheckerImpl()
+    : valid_thread_id_(kInvalidThreadId) {
   EnsureThreadIdAssigned();
 }
 
-ThreadChecker::~ThreadChecker() {}
+ThreadCheckerImpl::~ThreadCheckerImpl() {}
 
-bool ThreadChecker::CalledOnValidThread() const {
+bool ThreadCheckerImpl::CalledOnValidThread() const {
   EnsureThreadIdAssigned();
   AutoLock auto_lock(lock_);
   return valid_thread_id_ == PlatformThread::CurrentId();
 }
 
-void ThreadChecker::DetachFromThread() {
+void ThreadCheckerImpl::DetachFromThread() {
   AutoLock auto_lock(lock_);
   valid_thread_id_ = kInvalidThreadId;
 }
 
-void ThreadChecker::EnsureThreadIdAssigned() const {
+void ThreadCheckerImpl::EnsureThreadIdAssigned() const {
   AutoLock auto_lock(lock_);
   if (valid_thread_id_ != kInvalidThreadId)
     return;
@@ -34,5 +32,3 @@ void ThreadChecker::EnsureThreadIdAssigned() const {
 }
 
 }  // namespace base
-
-#endif  // NDEBUG