Add support for backgrounding processes on the Mac

base/process/process.h

Index: base/process/process.h
diff --git a/base/process/process.h b/base/process/process.h
index a834a29acd1ca98a380f5a526c5e4c46b1952e2b..f272bc25fb31ff37dc9e76ea47c5bcefd174e865 100644
--- a/base/process/process.h
+++ b/base/process/process.h
@@ -105,6 +105,24 @@ class BASE_EXPORT Process {
   // Same as WaitForExit() but only waits for up to |timeout|.
   bool WaitForExitWithTimeout(TimeDelta timeout, int* exit_code);
 
+#if defined(OS_MACOSX)
+  // The Mac needs a Mach port in order to manipulate a process's priority,
+  // and there's no good way to get that from base:: given the pid. These
+  // Mac variants of the IsProcessBackgrounded and SetProcessBackgrounded API
+  // take the Mach port for this reason. See crbug.com/460102
+  //
+  // A process is backgrounded when it's priority is lower than normal.
+  // Return true if the process with mach port |process_port| is backgrounded,
+  // false otherwise.
+  bool IsProcessBackgrounded(mach_port_t process_port) const;
+
+  // Set the process with the specified mach port as backgrounded. If value is
+  // true, the priority of the process will be lowered. If value is false, the
+  // priority of the process will be made "normal" - equivalent to default
+  // process priority. Returns true if the priority was changed, false
+  // otherwise.
+  bool SetProcessBackgrounded(mach_port_t process_port, bool value);
+#else
   // A process is backgrounded when it's priority is lower than normal.
   // Return true if this process is backgrounded, false otherwise.
   bool IsProcessBackgrounded() const;
@@ -114,7 +132,7 @@ class BASE_EXPORT Process {
   // will be made "normal" - equivalent to default process priority.
   // Returns true if the priority was changed, false otherwise.
   bool SetProcessBackgrounded(bool value);
-
+#endif  // defined(OS_MACOSX)
   // Returns an integer representing the priority of a process. The meaning
   // of this value is OS dependent.
   int GetPriority() const;