Remove memory_pressure component.

components/memory_pressure/memory_pressure_listener.cc

Index: components/memory_pressure/memory_pressure_listener.cc
diff --git a/components/memory_pressure/memory_pressure_listener.cc b/components/memory_pressure/memory_pressure_listener.cc
deleted file mode 100644
index 3d2fe1a9b3cd027aa70e2c40809931ecd9dc3088..0000000000000000000000000000000000000000
--- a/components/memory_pressure/memory_pressure_listener.cc
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright 2015 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.
-
-#include "components/memory_pressure/memory_pressure_listener.h"
-
-#include "base/lazy_instance.h"
-#include "base/observer_list_threadsafe.h"
-#include "base/trace_event/trace_event.h"
-
-namespace memory_pressure {
-
-namespace {
-
-// ObserverListThreadSafe is RefCountedThreadSafe, this traits is needed
-// to ensure the LazyInstance will hold a reference to it.
-struct LeakyLazyObserverListTraits
-    : base::internal::LeakyLazyInstanceTraits<
-          base::ObserverListThreadSafe<MemoryPressureListener>> {
-  static base::ObserverListThreadSafe<MemoryPressureListener>* New(
-      void* instance) {
-    base::ObserverListThreadSafe<MemoryPressureListener>* ret =
-        base::internal::LeakyLazyInstanceTraits<base::ObserverListThreadSafe<
-            MemoryPressureListener>>::New(instance);
-    // Leaky.
-    ret->AddRef();
-    return ret;
-  }
-};
-
-base::LazyInstance<base::ObserverListThreadSafe<MemoryPressureListener>,
-                   LeakyLazyObserverListTraits> g_observers =
-    LAZY_INSTANCE_INITIALIZER;
-
-}  // namespace
-
-MemoryPressureListener::MemoryPressureListener(
-    const MemoryPressureListener::MemoryPressureCallback& callback)
-    : callback_(callback) {
-  g_observers.Get().AddObserver(this);
-}
-
-MemoryPressureListener::~MemoryPressureListener() {
-  g_observers.Get().RemoveObserver(this);
-}
-
-void MemoryPressureListener::Notify(MemoryPressureLevel memory_pressure_level) {
-  callback_.Run(memory_pressure_level);
-}
-
-// static
-void MemoryPressureListener::NotifyMemoryPressure(
-    MemoryPressureLevel memory_pressure_level) {
-  DCHECK_NE(memory_pressure_level, MEMORY_PRESSURE_LEVEL_NONE);
-  TRACE_EVENT1("memory", "MemoryPressureListener::NotifyMemoryPressure",
-               "level", memory_pressure_level);
-  g_observers.Get().Notify(FROM_HERE, &MemoryPressureListener::Notify,
-                           memory_pressure_level);
-}
-
-}  // namespace memory_pressure