Remove dead includes in folly/synchronization

Reviewed By: yfeldblum

Differential Revision: D18298354

fbshipit-source-id: 683da223956570304a9ba80dacfb4659ff9a114b

folly/synchronization/test/BatonBenchmark.cpp

@@ -23,7 +23,6 @@
 #include <folly/synchronization/test/BatonTestHelpers.h>
 #include <folly/test/DeterministicSchedule.h>
 
-using namespace folly;
 using namespace folly::test;
 using folly::detail::EmulatedFutexAtomic;
 

folly/synchronization/test/BatonTest.cpp

@@ -22,7 +22,6 @@
 #include <folly/synchronization/test/BatonTestHelpers.h>
 #include <folly/test/DeterministicSchedule.h>
 
-using namespace folly;
 using namespace folly::test;
 using folly::detail::EmulatedFutexAtomic;
 using std::chrono::steady_clock;

folly/synchronization/test/DistributedMutexTest.cpp

@@ -589,7 +589,6 @@ TEST(DistributedMutex, BasicTryLock) {
 }
 
 TEST(DistributedMutex, TestSingleElementContentionChain) {
-  using namespace folly::detail;
 
   // Acquire the mutex once, let another thread form a contention chain on the
   // mutex, and then release it.  Observe the other thread grab the lock
@@ -621,7 +620,6 @@ TEST(DistributedMutex, TestSingleElementContentionChain) {
 }
 
 TEST(DistributedMutex, TestTwoElementContentionChain) {
-  using namespace folly::detail;
 
   // Acquire the mutex once, let another thread form a contention chain on the
   // mutex, and then release it.  Observe the other thread grab the lock
@@ -669,7 +667,6 @@ TEST(DistributedMutex, TestTwoElementContentionChain) {
 }
 
 TEST(DistributedMutex, TestTwoContentionChains) {
-  using namespace folly::detail;
 
   auto&& schedule = test::ManualSchedule{};
   auto&& mutex = test::TestDistributedMutex<test::ManualAtomic>{};

folly/synchronization/test/SemaphoreTest.cpp

@@ -28,7 +28,6 @@
 #include <folly/portability/SysMman.h>
 #include <folly/synchronization/test/Barrier.h>
 
-using namespace std::literals::chrono_literals;
 
 using namespace folly::test;
 

folly/synchronization/test/SmallLocksTest.cpp

@@ -37,7 +37,6 @@
 using folly::MicroLock;
 using folly::MicroSpinLock;
 using folly::MSLGuard;
-using std::string;
 
 #ifdef FOLLY_PICO_SPIN_LOCK_H_
 using folly::PicoSpinLock;