Fix tab backgrounding on Linux / ChromeOS

base/process.h

 // Copyright (c) 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.
 
 #ifndef BASE_PROCESS_H_
 #define BASE_PROCESS_H_
 #pragma once
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
@@ skipping 16 matching lines @@
 const ProcessHandle kNullProcessHandle = NULL;
 const ProcessId kNullProcessId = 0;
 #elif defined(OS_POSIX)
 // On POSIX, our ProcessHandle will just be the PID.
 typedef pid_t ProcessHandle;
 typedef pid_t ProcessId;
 const ProcessHandle kNullProcessHandle = 0;
 const ProcessId kNullProcessId = 0;
 #endif  // defined(OS_WIN)
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-// saved_priority_ will be set to this to indicate that it's not holding
-// a valid value. -20 to 19 are valid process priorities.
-const int kUnsetProcessPriority = 256;
-#endif
-
 class BASE_EXPORT Process {
  public:
   Process() : process_(kNullProcessHandle) {
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-    saved_priority_ = kUnsetProcessPriority;
-#endif
   }
 
   explicit Process(ProcessHandle handle) : process_(handle) {
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-    saved_priority_ = kUnsetProcessPriority;
-#endif
   }
 
   // A handle to the current process.
   static Process Current();
 
+  static bool CanBackgroundProcesses();
+
   // Get/Set the handle for this process. The handle will be 0 if the process
   // is no longer running.
   ProcessHandle handle() const { return process_; }
   void set_handle(ProcessHandle handle) {
     process_ = handle;
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-    saved_priority_ = kUnsetProcessPriority;
-#endif
   }
 
   // Get the PID for this process.
   ProcessId pid() const;
 
   // Is the this process the current process.
   bool is_current() const;
 
   // Close the process handle. This will not terminate the process.
   void Close();
@@ skipping 13 matching lines @@
   // process priority.
   // Returns true if the priority was changed, false otherwise.
   bool SetProcessBackgrounded(bool value);
 
   // Returns an integer representing the priority of a process. The meaning
   // of this value is OS dependent.
   int GetPriority() const;
 
  private:
   ProcessHandle process_;
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-  // Holds the priority that the process was set to when it was backgrounded.
-  // If the process wasn't backgrounded it will be kUnsetProcessPriority.
-  int saved_priority_;
-#endif
 };
 
 }  // namespace base
 
 #endif  // BASE_PROCESS_H_