Adds MemoryPressureListener.

base/android/memory_pressure_listener_android.cc

Index: base/android/memory_pressure_listener_android.cc
diff --git a/base/android/memory_pressure_listener_android.cc b/base/android/memory_pressure_listener_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..72a598acfae70ea86397657b4ed831ed388efa9b
--- /dev/null
+++ b/base/android/memory_pressure_listener_android.cc
@@ -0,0 +1,31 @@
+// 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.
+
+#include "base/android/memory_pressure_listener_android.h"
+
+#include "base/memory/memory_pressure_listener.h"
+#include "jni/MemoryPressureListener_jni.h"
+
+// Defined and called by JNI.
+static void OnMemoryPressure(
+    JNIEnv* env, jclass clazz, jint memory_pressure_level) {
+  base::MemoryPressureListener::NotifyMemoryPressure(
+      static_cast<base::MemoryPressureListener::MemoryPressureLevel>(
+          memory_pressure_level));
+}
+
+namespace base {
+namespace android {
+
+bool MemoryPressureListenerAndroid::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+void MemoryPressureListenerAndroid::RegisterSystemCallback(JNIEnv* env) {
+  Java_MemoryPressureListener_registerSystemCallback(
+      env, GetApplicationContext());
+}
+
+}  // namespace android
+}  // namespace base