Update from https://crrev.com/333737

base/process/process_posix.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/process/process.h"
 
 #include <sys/resource.h>
 #include <sys/wait.h>
 
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
@@ skipping 174 matching lines @@
 #else
     // Currently on Linux we can't handle non child processes.
     NOTIMPLEMENTED();
 #endif  // OS_MACOSX
   }
 
   int status;
   if (!WaitpidWithTimeout(handle, &status, timeout))
     return false;
   if (WIFSIGNALED(status)) {
-    *exit_code = -1;
+    if (exit_code)
+      *exit_code = -1;
     return true;
   }
   if (WIFEXITED(status)) {
-    *exit_code = WEXITSTATUS(status);
+    if (exit_code)
+      *exit_code = WEXITSTATUS(status);
     return true;
   }
   return false;
 }
 #endif  // !defined(OS_NACL_NONSFI)
 
 }  // namespace
 
 namespace base {
 
@@ skipping 35 matching lines @@
   // On POSIX there are no privileges to set.
   return Open(pid);
 }
 
 // static
 Process Process::DeprecatedGetProcessFromHandle(ProcessHandle handle) {
   DCHECK_NE(handle, GetCurrentProcessHandle());
   return Process(handle);
 }
 
-#if !defined(OS_LINUX)
+#if !defined(OS_LINUX) && !defined(OS_MACOSX)
 // static
 bool Process::CanBackgroundProcesses() {
   return false;
 }
-#endif  // !defined(OS_LINUX)
+#endif  // !defined(OS_LINUX) && !defined(OS_MACOSX)
 
 bool Process::IsValid() const {
   return process_ != kNullProcessHandle;
 }
 
 ProcessHandle Process::Handle() const {
   return process_;
 }
 
 Process Process::Duplicate() const {
@@ skipping 74 matching lines @@
 #endif  // !defined(OS_NACL_NONSFI)
 
 bool Process::WaitForExit(int* exit_code) {
   return WaitForExitWithTimeout(TimeDelta::Max(), exit_code);
 }
 
 bool Process::WaitForExitWithTimeout(TimeDelta timeout, int* exit_code) {
   return WaitForExitWithTimeoutImpl(Handle(), exit_code, timeout);
 }
 
-#if !defined(OS_LINUX)
+#if !defined(OS_LINUX) && !defined(OS_MACOSX)
 bool Process::IsProcessBackgrounded() const {
   // See SetProcessBackgrounded().
   DCHECK(IsValid());
   return false;
 }
 
 bool Process::SetProcessBackgrounded(bool value) {
-  // POSIX only allows lowering the priority of a process, so if we
-  // were to lower it we wouldn't be able to raise it back to its initial
-  // priority.
-  DCHECK(IsValid());
+  // Not implemented for POSIX systems other than Mac and Linux. With POSIX, if
+  // we were to lower the process priority we wouldn't be able to raise it back
+  // to its initial priority.
+  NOTIMPLEMENTED();
   return false;
 }
-#endif  // !defined(OS_LINUX)
+#endif  // !defined(OS_LINUX) && !defined(OS_MACOSX)
 
 int Process::GetPriority() const {
   DCHECK(IsValid());
   return getpriority(PRIO_PROCESS, process_);
 }
 
 }  // namespace base