base: Introduce SharedMemoryTracker for POSIX (but not macOS)

base/BUILD.gn

 # 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 501 matching lines @@
     "memory/ref_counted.h",
     "memory/ref_counted_delete_on_sequence.h",
     "memory/ref_counted_memory.cc",
     "memory/ref_counted_memory.h",
     "memory/scoped_policy.h",
     "memory/scoped_vector.h",
     "memory/shared_memory.h",
     "memory/shared_memory_android.cc",
     "memory/shared_memory_handle.h",
     "memory/shared_memory_handle_mac.cc",
+    "memory/shared_memory_handle_posix.cc",
     "memory/shared_memory_handle_win.cc",
     "memory/shared_memory_helper.cc",
     "memory/shared_memory_helper.h",
     "memory/shared_memory_mac.cc",
     "memory/shared_memory_nacl.cc",
     "memory/shared_memory_posix.cc",
+    "memory/shared_memory_tracker.cc",
+    "memory/shared_memory_tracker.h",
     "memory/shared_memory_win.cc",
     "memory/singleton.cc",
     "memory/singleton.h",
     "memory/weak_ptr.cc",
     "memory/weak_ptr.h",
     "message_loop/incoming_task_queue.cc",
     "message_loop/incoming_task_queue.h",
     "message_loop/message_loop.cc",
     "message_loop/message_loop.h",
     "message_loop/message_loop_task_runner.cc",
@@ skipping 855 matching lines @@
       "bsm",
       "CoreFoundation.framework",
       "IOKit.framework",
       "Security.framework",
     ]
   }
 
   # Mac or iOS.
   if (is_mac || is_ios) {
     sources -= [
+      "memory/shared_memory_handle_posix.cc",
       "memory/shared_memory_posix.cc",
       "native_library_posix.cc",
       "strings/sys_string_conversions_posix.cc",
       "threading/platform_thread_internal_posix.cc",
     ]
   } else {
     # Non-Mac/ios.
     sources -= [
       "files/file_path_watcher_fsevents.cc",
       "files/file_path_watcher_fsevents.h",
@@ skipping 97 matching lines @@
       "mac/scoped_mach_port.h",
       "mac/scoped_mach_vm.cc",
       "mac/scoped_mach_vm.h",
       "mac/scoped_nsautorelease_pool.h",
       "mac/scoped_nsautorelease_pool.mm",
       "mac/scoped_nsobject.h",
       "mac/scoped_nsobject.mm",
       "mac/scoped_objc_class_swizzler.h",
       "mac/scoped_objc_class_swizzler.mm",
       "mac/scoped_typeref.h",
+      "memory/shared_memory_handle_posix.cc",
       "memory/shared_memory_posix.cc",
       "message_loop/message_pump_mac.h",
       "message_loop/message_pump_mac.mm",
       "power_monitor/power_monitor_device_source_ios.mm",
       "process/memory_stubs.cc",
       "strings/sys_string_conversions_mac.mm",
       "threading/platform_thread_mac.mm",
       "time/time_mac.cc",
     ]
 
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
   if (is_posix && !is_mac && !is_ios && !is_android && !is_chromeos) {
     sources += [ "power_monitor/power_monitor_device_source_posix.cc" ]
   }
 
+  if (!(is_posix && !is_mac)) {

[danakj, 2017/01/25 16:58:12]

can you write this without double negatives?

also while most of this uses sources -= [] we'd like to move toward using
sources += [] instead only. Can you do that with these new files?

[hajimehoshi, 2017/01/26 10:56:00]

Done.

+    sources -= [
+      "memory/shared_memory_tracker.cc",
+      "memory/shared_memory_tracker.h",
+    ]
+  }
+
   if (!use_glib) {
     sources -= [
       "message_loop/message_pump_glib.cc",
       "message_loop/message_pump_glib.h",
     ]
   }
 
   if (using_sanitizer) {
     data += [ "//tools/valgrind/asan/" ]
     if (is_win) {
@@ skipping 1040 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }