Update from https://crrev.com/329939

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index e7985ef47311ce2be7ee27377aba78b2992d35c4..2170520185d2cf813a8159159305b64a280fbb6c 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -216,6 +216,8 @@ component("base") {
     "files/file_posix.cc",
     "files/file_proxy.cc",
     "files/file_proxy.h",
+    "files/file_tracing.cc",
+    "files/file_tracing.h",
     "files/file_util.cc",
     "files/file_util.h",
     "files/file_util_android.cc",
@@ -269,6 +271,8 @@ component("base") {
     "mac/bundle_locations.h",
     "mac/bundle_locations.mm",
     "mac/cocoa_protocols.h",
+    "mac/dispatch_source_mach.cc",
+    "mac/dispatch_source_mach.h",
     "mac/foundation_util.h",
     "mac/foundation_util.mm",
     "mac/launch_services_util.cc",
@@ -599,6 +603,8 @@ component("base") {
     "win/iat_patch_function.h",
     "win/iunknown_impl.cc",
     "win/iunknown_impl.h",
+    "win/memory_pressure_monitor.cc",
+    "win/memory_pressure_monitor.h",
     "win/message_window.cc",
     "win/message_window.h",
     "win/metro.cc",
@@ -1146,6 +1152,7 @@ test("base_unittests") {
     "lazy_instance_unittest.cc",
     "logging_unittest.cc",
     "mac/bind_objc_block_unittest.mm",
+    "mac/dispatch_source_mach_unittest.cc",
     "mac/foundation_util_unittest.mm",
     "mac/libdispatch_task_runner_unittest.cc",
     "mac/mac_util_unittest.mm",
@@ -1282,6 +1289,7 @@ test("base_unittests") {
     "win/event_trace_provider_unittest.cc",
     "win/i18n_unittest.cc",
     "win/iunknown_impl_unittest.cc",
+    "win/memory_pressure_monitor_unittest.cc",
     "win/message_window_unittest.cc",
     "win/object_watcher_unittest.cc",
     "win/pe_image_unittest.cc",