Add MemoryMonitorAndroid

content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java

Index: content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java b/content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java
new file mode 100644
index 0000000000000000000000000000000000000000..0fa1e03b42803ca14cda4b2365b932d51a39de0c
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java
@@ -0,0 +1,42 @@
+// Copyright 2016 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.
+
+package org.chromium.content.browser;
+
+import android.app.ActivityManager;
+import android.content.Context;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * Android implementation of MemoryMonitor.
+ */
+@JNINamespace("content")
+class MemoryMonitorAndroid {
+    private static final ActivityManager.MemoryInfo sMemoryInfo =
+            new ActivityManager.MemoryInfo();
+
+    /**
+     * Get the current MemoryInfo from ActivityManager and invoke the native
+     * callback to populate the MemoryInfo.
+     *
+     * @param context The context of the application.
+     * @param outPtr A native output pointer to populate MemoryInfo. This is
+     * passed back to the native callback.
+     */
+    @CalledByNative
+    private static void getMemoryInfo(Context context, long outPtr) {
+        ActivityManager am = (ActivityManager) context.getSystemService(
+                Context.ACTIVITY_SERVICE);
+        am.getMemoryInfo(sMemoryInfo);
+        nativeGetMemoryInfoCallback(
+                sMemoryInfo.availMem, sMemoryInfo.lowMemory,
+                sMemoryInfo.threshold, sMemoryInfo.totalMem, outPtr);
+    }
+
+    private static native void nativeGetMemoryInfoCallback(
+            long availMem, boolean lowMemory,
+            long threshold, long totalMem, long outPtr);
+}