Add support for backgrounding processes on the Mac

base/process/process_posix.cc

Index: base/process/process_posix.cc
diff --git a/base/process/process_posix.cc b/base/process/process_posix.cc
index 1c4210b0fe590380503ced3c94cf98d01405ff44..f9223a7c3a3fc05a6f7a0fc46f4a8581c199ebd5 100644
--- a/base/process/process_posix.cc
+++ b/base/process/process_posix.cc
@@ -249,12 +249,12 @@ Process Process::DeprecatedGetProcessFromHandle(ProcessHandle handle) {
   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;
@@ -304,7 +304,7 @@ 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());
@@ -312,13 +312,13 @@ bool Process::IsProcessBackgrounded() const {
 }
 
 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());