Remove old Sleep and PostDelayedTask interfaces that use int ms instead of TimeDelta.

base/threading/platform_thread_posix.cc

Index: base/threading/platform_thread_posix.cc
diff --git a/base/threading/platform_thread_posix.cc b/base/threading/platform_thread_posix.cc
index 24bf3d2b8a565e86538d2f06b96c0b40df2f125a..e44c695ad5725b002c3bfff5709f0cc77a3b57f2 100644
--- a/base/threading/platform_thread_posix.cc
+++ b/base/threading/platform_thread_posix.cc
@@ -152,13 +152,6 @@ void PlatformThread::YieldCurrentThread() {
 }
 
 // static
-void PlatformThread::Sleep(int duration_ms) {
-  // NOTE: This function will be supplanted by the other version of Sleep
-  // in the future.  See issue 108171 for more information.
-  Sleep(TimeDelta::FromMilliseconds(duration_ms));
-}
-
-// static
 void PlatformThread::Sleep(TimeDelta duration) {
   struct timespec sleep_time, remaining;