Android: Integrates native and java SystemMonitor.

base/android/java/src/org/chromium/base/SystemMonitor.java

Index: base/android/java/src/org/chromium/base/SystemMonitor.java
diff --git a/base/android/java/src/org/chromium/base/SystemMonitor.java b/base/android/java/src/org/chromium/base/SystemMonitor.java
new file mode 100644
index 0000000000000000000000000000000000000000..7297b52a16c0acb5f319c550b7328f5e0d457092
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/SystemMonitor.java
@@ -0,0 +1,56 @@
+// Copyright (c) 2012 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.base;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.BatteryManager;
+import android.os.Looper;
+
+
+/**
+ * Integrates native SystemMonitor with the java side.
+ */
+@JNINamespace("base::android")
+public class SystemMonitor {
+
+    private static SystemMonitor sInstance;
+
+    private boolean mIsCharging;
+
+    public static void create(Context context) {
+        if (sInstance == null) {
+            sInstance = new SystemMonitor();
+            IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
+            Intent batteryStatusIntent = context.registerReceiver(null, ifilter);
+            onBatteryChargingChanged(batteryStatusIntent);
+        }
+    }
+
+    private SystemMonitor() {
+    }
+
+    public static void onBatteryChargingChanged(Intent intent) {
+        if (sInstance == null) {
+            // We may be called by the framework intent-filter before being
+            // fully initialized. This is not a problem, since our constructor
+            // will check for the state later on.
+            return;
+        }
+        int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
+        sInstance.mIsCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||
+                                status == BatteryManager.BATTERY_STATUS_FULL;

[vandebo (ex-Chrome), 2012/10/04 19:19:22]

If the battery is full, then we're not charging, true, but that doesn't mean
that we're on battery power either.  If there's a good reason to do this, then a
comment might be appropriate.

[bulach, 2012/10/05 13:12:30]

oh, good point! using the "BATTERY_PLUGGED_" status instead.

+        nativeOnBatteryChargingChanged();
+    }
+
+    @CalledByNative
+    private static boolean isBatteryPower() {
+        return sInstance.mIsCharging;
+    }
+
+    private static native void nativeOnBatteryChargingChanged();
+
+}