Modify ThreadChecker and NonThreadSafe so that their functionality is

net/url_request/url_request_throttler_manager.cc

Index: net/url_request/url_request_throttler_manager.cc
diff --git a/net/url_request/url_request_throttler_manager.cc b/net/url_request/url_request_throttler_manager.cc
index 07e3bb6ab0facd97fbd64e3eb7500c4ab52b060e..25f6e86e7b1adfb202045720582af68888161b93 100644
--- a/net/url_request/url_request_throttler_manager.cc
+++ b/net/url_request/url_request_throttler_manager.cc
@@ -33,31 +33,6 @@ struct IteratorHistory {
 
 namespace net {
 
-ThreadCheckerForRelease::ThreadCheckerForRelease()
-    : valid_thread_id_(base::kInvalidThreadId) {
-  EnsureThreadIdAssigned();
-}
-
-ThreadCheckerForRelease::~ThreadCheckerForRelease() {}
-
-bool ThreadCheckerForRelease::CalledOnValidThread() const {
-  EnsureThreadIdAssigned();
-  base::AutoLock auto_lock(lock_);
-  return valid_thread_id_ == base::PlatformThread::CurrentId();
-}
-
-void ThreadCheckerForRelease::DetachFromThread() {
-  base::AutoLock auto_lock(lock_);
-  valid_thread_id_ = base::kInvalidThreadId;
-}
-
-void ThreadCheckerForRelease::EnsureThreadIdAssigned() const {
-  base::AutoLock auto_lock(lock_);
-  if (valid_thread_id_ != base::kInvalidThreadId)
-    return;
-  valid_thread_id_ = base::PlatformThread::CurrentId();
-}
-
 const unsigned int URLRequestThrottlerManager::kMaximumNumberOfEntries = 1500;
 const unsigned int URLRequestThrottlerManager::kRequestsBetweenCollecting = 200;
 
@@ -162,13 +137,13 @@ void URLRequestThrottlerManager::GarbageCollectEntries() {
   // is in common between the crash dumps.  Note that this is not equivalent
   // to the command line stored in the PEB of the minidump since it may
   // have been modified based on the about:labs preferences.
-  std::string command_line_string;
-#if defined(OS_WIN)
-  std::wstring wstr = CommandLine::ForCurrentProcess()->command_line_string();
-  command_line_string = WideToASCII(wstr);
-#else
-  command_line_string =
-      CommandLine::ForCurrentProcess()->command_line_string();
+  std::string command_line_string;
+#if defined(OS_WIN)
+  std::wstring wstr = CommandLine::ForCurrentProcess()->command_line_string();
+  command_line_string = WideToASCII(wstr);
+#else
+  command_line_string =
+      CommandLine::ForCurrentProcess()->command_line_string();
 #endif
   char command_line_buffer[400] = { 0 };
   base::strlcpy(command_line_buffer, command_line_string.c_str(),