Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeLifetimeController.java

+// 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.
+
+package org.chromium.chrome.browser;
+
+import android.app.Activity;
+import android.app.AlarmManager;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Process;
+import android.util.Log;
+
+import org.chromium.base.ActivityState;
+import org.chromium.base.ApplicationStatus;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Handles killing and potentially restarting Chrome's main Browser process.  Note that this class
+ * relies on main Chrome activities to properly call {@link Activity#finish()} on themselves so that
+ * it will be notified that all {@link Activity}s under this {@link Application} have been
+ * destroyed.
+ */
+class ChromeLifetimeController implements ApplicationLifetime.Observer,
+        ApplicationStatus.ActivityStateListener {
+    private static final String TAG = "ChromeLifetimeController";
+
+    private final Context mContext;
+    private boolean mRestartChromeOnDestroy;
+    private int mRemainingActivitiesCount = 0;
+
+    /**
+     * Creates a {@link ChromeLifetimeController} instance.
+     * @param context A {@link Context} instance.  The application context will be saved from this
+     *                one.
+     */
+    public ChromeLifetimeController(Context context) {
+        mContext = context.getApplicationContext();
+        ApplicationLifetime.addObserver(this);
+    }
+
+    @Override
+    public void onTerminate(boolean restart) {
+        mRestartChromeOnDestroy = restart;
+
+        // We've called terminate twice, just wait for the first call to take effect.
+        if (mRemainingActivitiesCount > 0) {
+            Log.w(TAG, "onTerminate called twice");
+            return;
+        }
+
+        for (WeakReference<Activity> weakActivity : ApplicationStatus.getRunningActivities()) {
+            Activity activity = weakActivity.get();
+            if (activity != null) {
+                ApplicationStatus.registerStateListenerForActivity(this, activity);
+                mRemainingActivitiesCount++;
+                activity.finish();
+            }
+        }
+    }
+
+
+    @Override
+    public void onActivityStateChange(Activity activity, int newState) {
+        assert mRemainingActivitiesCount > 0;
+        if (newState == ActivityState.DESTROYED) {
+            mRemainingActivitiesCount--;
+            if (mRemainingActivitiesCount == 0) {
+                destroyProcess();
+            }
+        }
+
+    }
+
+    private void destroyProcess() {
+        Handler handler = new Handler(Looper.getMainLooper());
+        handler.post(new Runnable() {
+            @Override
+            public void run() {
+                if (mRestartChromeOnDestroy) scheduleRestart(mContext);
+
+                Log.w(TAG, "Forcefully killing process...");
+                Process.killProcess(Process.myPid());
+
+                mRestartChromeOnDestroy = false;
+            }
+        });
+    }
+
+    private static void scheduleRestart(Context context) {
+        Intent intent = new Intent();
+        intent.setPackage(context.getPackageName());
+        intent.setAction(Intent.ACTION_MAIN);
+        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent,
+                PendingIntent.FLAG_ONE_SHOT);
+        if (pendingIntent != null) {
+            AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+            am.set(AlarmManager.RTC, System.currentTimeMillis() + 1000, pendingIntent);
+        }
+    }
+}