Split ProcessHandle and its related routines into base/process/process_handle.h.

base/process/process_metrics.h

 // Copyright (c) 2013 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.
 
 // This file contains routines for gathering resource statistics for processes
 // running on the system.
 
 #ifndef BASE_PROCESS_PROCESS_METRICS_H_
 #define BASE_PROCESS_PROCESS_METRICS_H_
 
@@ skipping 219 matching lines @@
   // Gem data will be -1 if not supported.
   int gem_objects;
   long long gem_size;
 };
 // Retrieves data from /proc/meminfo about system-wide memory consumption.
 // Fills in the provided |meminfo| structure. Returns true on success.
 // Exposed for memory debugging widget.
 BASE_EXPORT bool GetSystemMemoryInfo(SystemMemoryInfoKB* meminfo);
 #endif  // defined(OS_LINUX) || defined(OS_ANDROID)
 
+#if defined(OS_LINUX) || defined(OS_ANDROID)
+// Get the number of threads of |process| as available in /proc/<pid>/stat.
+// This should be used with care as no synchronization with running threads is
+// done. This is mostly useful to guarantee being single-threaded.
+// Returns 0 on failure.
+BASE_EXPORT int GetNumberOfThreads(ProcessHandle process);
+
+// /proc/self/exe refers to the current executable.
+BASE_EXPORT extern const char kProcSelfExe[];
+#endif  // defined(OS_LINUX) || defined(OS_ANDROID)
+
+#if defined(OS_POSIX)
+// Returns the maximum number of file descriptors that can be open by a process
+// at once. If the number is unavailable, a conservative best guess is returned.
+size_t GetMaxFds();
+#endif  // defined(OS_POSIX)
+
 }  // namespace base
 
 #endif  // BASE_PROCESS_PROCESS_METRICS_H_