Stop warnings resulting from unimplemented SetProcessBackgrounded().

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 367606c2d625d78353d133648f0627155b024902..72e49faefca970303b91ecc66f24d3b79af27caf 100644
--- a/base/process/process_posix.cc
+++ b/base/process/process_posix.cc
@@ -364,9 +364,9 @@ bool Process::IsProcessBackgrounded() const {
 }
 
 bool Process::SetProcessBackgrounded(bool value) {
-  // 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.
+  // Not implemented for POSIX systems other than 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;
 }