From 399b98c7516992ad1c718c0932e1608e609b8b64 Mon Sep 17 00:00:00 2001
From: dfalcantara <dfalcantara@chromium.org>
Date: Wed, 5 Aug 2015 18:32:01 -0700
Subject: [PATCH] Restart Chrome by killing it with an out-of-process Activity.

As of KK, Android's AlarmManager has a minimum of 5 seconds before
an alarm may be fired, which means that restarting Chrome via an alarm
takes an inordinate amount of time.  Switch to using an Activity
that runs in a separate process and:
1) Kills the main Chrome process
2) Fires an Intent to restart the main Chrome Activity
3) Immediately kills its own process.

BUG=519519

Review URL: https://codereview.chromium.org/1276703002

Cr-Commit-Position: refs/heads/master@{#342042}
---
 chrome/android/java/AndroidManifest.xml            |  9 +++++
 .../chrome/browser/BrowserRestartActivity.java     | 42 ++++++++++++++++++++++
 .../chrome/browser/ChromeLifetimeController.java   | 37 ++++++++-----------
 3 files changed, 66 insertions(+), 22 deletions(-)
 create mode 100644 chrome/android/java/src/org/chromium/chrome/browser/BrowserRestartActivity.java

diff --git a/chrome/android/java/AndroidManifest.xml b/chrome/android/java/AndroidManifest.xml
index 41e60c9d6fc8..27a657bd4ee9 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -389,6 +389,15 @@ by a child template that "extends" this file.
             android:hardwareAccelerated="false">
         </activity>
 
+        <!-- This activity is used to restart the main Chrome process.  Should never be exported. -->
+        <activity android:name="org.chromium.chrome.browser.BrowserRestartActivity"
+            android:launchMode="singleInstance"
+            android:exported="false"
+            android:theme="@android:style/Theme.NoDisplay"
+            android:excludeFromRecents="true"
+            android:process=":browser_restart_process">
+        </activity>
+
         <!-- Providers for chrome data. -->
         <provider android:name="org.chromium.chrome.browser.ChromeBrowserProvider"
             android:authorities="{{ manifest_package }}.ChromeBrowserProvider;{{ manifest_package }}.browser;{{ manifest_package }}"
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/BrowserRestartActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/BrowserRestartActivity.java
new file mode 100644
index 000000000000..17cb5408486f
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/BrowserRestartActivity.java
@@ -0,0 +1,42 @@
+// 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.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Process;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.chrome.browser.util.IntentUtils;
+
+/**
+ * Activity that kills and restarts Chrome, then immediately kills itself.
+ * Works around an Android framework issue for alarms set via the AlarmManager: crbug.com/515919.
+ */
+public class BrowserRestartActivity extends Activity {
+    static final String EXTRA_PID = "org.chromium.chrome.browser.BrowserRestartActivity.pid";
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        int pid = IntentUtils.safeGetIntExtra(getIntent(), BrowserRestartActivity.EXTRA_PID, -1);
+        if (pid != -1) {
+            Process.killProcess(pid);
+
+            // Restart Chrome.
+            Context context = ApplicationStatus.getApplicationContext();
+            Intent intent = new Intent(Intent.ACTION_MAIN);
+            intent.setPackage(context.getPackageName());
+            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            context.startActivity(intent);
+        }
+
+        finish();
+        Process.killProcess(Process.myPid());
+    }
+}
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeLifetimeController.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeLifetimeController.java
index 0cc4c8f0b9de..b433b50d6bbb 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeLifetimeController.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeLifetimeController.java
@@ -5,17 +5,15 @@
 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 org.chromium.base.Log;
 
 import java.lang.ref.WeakReference;
 
@@ -27,7 +25,7 @@ import java.lang.ref.WeakReference;
  */
 class ChromeLifetimeController implements ApplicationLifetime.Observer,
         ApplicationStatus.ActivityStateListener {
-    private static final String TAG = "ChromeLifetimeController";
+    private static final String TAG = "cr.LifetimeController";
 
     // The amount of time to wait for Chrome to destroy all the activities.
     private static final long WATCHDOG_DELAY = 1000;
@@ -95,26 +93,21 @@ class ChromeLifetimeController implements ApplicationLifetime.Observer,
         mHandler.post(new Runnable() {
             @Override
             public void run() {
-                if (mRestartChromeOnDestroy) scheduleRestart(mContext);
-
-                Log.w(TAG, "Forcefully killing process...");
-                Process.killProcess(Process.myPid());
-
+                if (mRestartChromeOnDestroy) {
+                    Log.w(TAG, "Launching BrowserRestartActivity to restart Chrome.");
+                    Context context = ApplicationStatus.getApplicationContext();
+                    Intent intent = new Intent();
+                    intent.setClassName(
+                            context.getPackageName(), BrowserRestartActivity.class.getName());
+                    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+                    intent.putExtra(BrowserRestartActivity.EXTRA_PID, Process.myPid());
+                    context.startActivity(intent);
+                } else {
+                    Log.w(TAG, "Killing process directly.");
+                    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);
-        }
-    }
 }
-- 
2.11.4.GIT