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..9053da8927fd739279c81716afc09ea1aa60a9f9
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java
@@ -0,0 +1,26 @@
+// 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 {
+    @CalledByNative
+    private static ActivityManager.MemoryInfo getMemoryInfo(Context context) {
+        ActivityManager am = (ActivityManager) context.getSystemService(
+                Context.ACTIVITY_SERVICE);
+        ActivityManager.MemoryInfo info = new ActivityManager.MemoryInfo();

[boliu, 2016/09/27 03:00:23]

actually, to avoid gc churn, can you save this object instead of allocating in
every call? is there any sense how frequently this will be called?

[bashi, 2016/09/27 03:51:36]

Done. It's still unclear how much we call this function, but a delta between
calls is at least greater than seconds.

+        am.getMemoryInfo(info);
+        return info;
+    }
+}