Remove unused locking functionality from base::SharedMemory.

base/memory/shared_memory_posix.cc

Index: base/memory/shared_memory_posix.cc
diff --git a/base/memory/shared_memory_posix.cc b/base/memory/shared_memory_posix.cc
index 722a0b36767854411740cf14ca8d7d0c1ae36841..0ca75ba274cbd06ffa56d0442068304bb4c35b04 100644
--- a/base/memory/shared_memory_posix.cc
+++ b/base/memory/shared_memory_posix.cc
@@ -4,26 +4,19 @@
 
 #include "base/memory/shared_memory.h"
 
-#include <errno.h>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
-#include <sys/types.h>
 #include <unistd.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
-#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/process/process_metrics.h"
 #include "base/profiler/scoped_tracker.h"
-#include "base/safe_strerror_posix.h"
 #include "base/scoped_generic.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/platform_thread.h"
-#include "base/threading/thread_restrictions.h"
 
 #if defined(OS_MACOSX)
 #include "base/mac/foundation_util.h"
@@ -38,8 +31,6 @@ namespace base {
 
 namespace {
 
-LazyInstance<Lock>::Leaky g_thread_lock_ = LAZY_INSTANCE_INITIALIZER;
-
 struct ScopedPathUnlinkerTraits {
   static FilePath* InvalidValue() { return nullptr; }
 
@@ -432,16 +423,6 @@ void SharedMemory::Close() {
   }
 }
 
-void SharedMemory::LockDeprecated() {
-  g_thread_lock_.Get().Acquire();
-  LockOrUnlockCommon(F_LOCK);
-}
-
-void SharedMemory::UnlockDeprecated() {
-  LockOrUnlockCommon(F_ULOCK);
-  g_thread_lock_.Get().Release();
-}
-
 #if !defined(OS_ANDROID)
 bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {
   DCHECK_EQ(-1, mapped_file_);
@@ -510,25 +491,6 @@ bool SharedMemory::FilePathForMemoryName(const std::string& mem_name,
 }
 #endif  // !defined(OS_ANDROID)
 
-void SharedMemory::LockOrUnlockCommon(int function) {
-  DCHECK_GE(mapped_file_, 0);
-  while (lockf(mapped_file_, function, 0) < 0) {
-    if (errno == EINTR) {
-      continue;
-    } else if (errno == ENOLCK) {
-      // temporary kernel resource exaustion
-      base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(500));
-      continue;
-    } else {
-      NOTREACHED() << "lockf() failed."
-                   << " function:" << function
-                   << " fd:" << mapped_file_
-                   << " errno:" << errno
-                   << " msg:" << safe_strerror(errno);
-    }
-  }
-}
-
 bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
                                         SharedMemoryHandle* new_handle,
                                         bool close_self,