Record swap metrics

content/browser/BUILD.gn

 # Copyright 2014 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/features.gni")
 import("//build/config/ui.gni")
 import("//gpu/vulkan/features.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
@@ skipping 966 matching lines @@
     "memory/memory_message_filter.cc",
     "memory/memory_message_filter.h",
     "memory/memory_monitor.cc",
     "memory/memory_monitor.h",
     "memory/memory_monitor_android.cc",
     "memory/memory_monitor_android.h",
     "memory/memory_monitor_win.cc",
     "memory/memory_monitor_win.h",
     "memory/memory_pressure_controller_impl.cc",
     "memory/memory_pressure_controller_impl.h",
+    "memory/swap_metrics_observer.cc",
+    "memory/swap_metrics_observer.h",
+    "memory/swap_metrics_observer_linux.cc",
+    "memory/swap_metrics_observer_linux.h",
+    "memory/swap_metrics_observer_mac.cc",
+    "memory/swap_metrics_observer_win.cc",
     "message_port_provider.cc",
     "mime_registry_impl.cc",
     "mime_registry_impl.h",
     "net/browser_online_state_observer.cc",
     "net/browser_online_state_observer.h",
     "net/network_errors_listing_ui.cc",
     "net/network_errors_listing_ui.h",
     "net/quota_policy_cookie_store.cc",
     "net/quota_policy_cookie_store.h",
     "net/view_blob_internals_job_factory.cc",
@@ skipping 854 matching lines @@
       "renderer_host/native_web_keyboard_event_android.cc",
       "renderer_host/render_widget_host_view_android.cc",
       "renderer_host/render_widget_host_view_android.h",
       "screen_orientation/screen_orientation_delegate_android.cc",
       "screen_orientation/screen_orientation_delegate_android.h",
       "web_contents/web_contents_android.cc",
       "web_contents/web_contents_android.h",
       "web_contents/web_contents_view_android.cc",
       "web_contents/web_contents_view_android.h",
     ]
+
+    set_sources_assignment_filter([])
+    sources += [
+      "memory/swap_metrics_observer_linux.cc",
+      "memory/swap_metrics_observer_linux.h",
+    ]
+    set_sources_assignment_filter(sources_assignment_filter)
+
     sources -= [
       "browser_ipc_logging.cc",
       "media/session/audio_focus_delegate_default.cc",
       "media/session/audio_focus_manager.cc",
       "media/session/audio_focus_manager.h",
       "tracing/tracing_ui.cc",
       "tracing/tracing_ui.h",
     ]
     deps += [
       "//content/public/android:jni",
@@ skipping 198 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }