base: Remove DiscardableMemoryMach.

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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
@@ skipping 715 matching lines @@
       "/DELAYLOAD:powrprof.dll",
       "/DELAYLOAD:setupapi.dll",
     ]
   } else if (!is_nacl) {
     # Non-Windows.
     deps += [ "//third_party/libevent" ]
   }
 
   # Mac.
   if (is_mac) {
-    sources += [
-      "memory/discardable_memory_mach.cc",
-      "memory/discardable_memory_mach.h",
-    ]
     sources -= [
       "native_library_posix.cc",
       "strings/sys_string_conversions_posix.cc",
     ]
   } else {
     # Non-Mac.
     sources -= [
       "files/file_path_watcher_fsevents.cc",
       "files/file_path_watcher_fsevents.h",
       "files/file_path_watcher_kqueue.cc",
@@ skipping 719 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }