Update from https://crrev.com/333737

base/memory/BUILD.gn

Index: base/memory/BUILD.gn
diff --git a/base/memory/BUILD.gn b/base/memory/BUILD.gn
index bd864caa245b32bb57dcf4737f08c87074ea69b4..c3442794d8c778dde20ff0636754d2a8660df0a4 100644
--- a/base/memory/BUILD.gn
+++ b/base/memory/BUILD.gn
@@ -18,6 +18,12 @@ source_set("memory") {
     "memory_pressure_listener.h",
     "memory_pressure_monitor.cc",
     "memory_pressure_monitor.h",
+    "memory_pressure_monitor_chromeos.cc",
+    "memory_pressure_monitor_chromeos.h",
+    "memory_pressure_monitor_mac.cc",
+    "memory_pressure_monitor_mac.h",
+    "memory_pressure_monitor_win.cc",
+    "memory_pressure_monitor_win.h",
     "raw_scoped_refptr_mismatch_checker.h",
     "ref_counted.cc",
     "ref_counted.h",
@@ -52,6 +58,12 @@ source_set("memory") {
     sources -= [ "shared_memory_nacl.cc" ]
   }
 
+  if (is_android) {
+    deps = [
+      "//third_party/ashmem",
+    ]
+  }
+
   configs += [ "//base:base_implementation" ]
 
   visibility = [ "//base/*" ]