[Mac] Maximise timer slack for background tabs

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index a9e8ab5577b3a83185d721a0eb6f64822dd87b9d..6c23369f246b82d3d4a036a5faf19e147783adfd 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -2013,16 +2013,19 @@ void RenderProcessHostImpl::SetBackgrounded(bool backgrounded) {
   // is to not invoke the SetPriorityClass API if the dll is loaded.
   if (GetModuleHandle(L"cbstext.dll"))
     return;
+#endif  // OS_WIN
 
-  // Windows Vista+ has a fancy process backgrounding mode that can only be set
-  // from within the process.  So notify the child process of background state.
+  // Notify the child process of background state.
   Send(new ChildProcessMsg_SetProcessBackgrounded(backgrounded));
-#else
 
+#if !defined(OS_WIN)
   // Backgrounding may require elevated privileges not available to renderer
   // processes, so control backgrounding from the process host.
+
+  // Windows Vista+ has a fancy process backgrounding mode that can only be set
+  // from within the process.
   child_process_launcher_->SetProcessBackgrounded(backgrounded);
-#endif  // OS_WIN
+#endif  // !OS_WIN
 }
 
 void RenderProcessHostImpl::OnProcessLaunched() {