✈ Remove unnecessary flag and DocumentModeManager.

chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
index edec565b76e2cf1d897d716c91e4d5ff07ca020d..f1ca36c7e2d422e4508aa9543fd082d9582866a3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
@@ -5,17 +5,12 @@
 package org.chromium.chrome.browser.document;
 
 import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
 import android.app.Activity;
-import android.app.ActivityManager;
-import android.app.ActivityManager.AppTask;
-import android.app.ActivityManager.RecentTaskInfo;
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.app.SearchManager;
 import android.content.Context;
 import android.content.Intent;
-import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.Uri;
@@ -52,7 +47,6 @@ import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.notifications.NotificationPlatformBridge;
 import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomizations;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
-import org.chromium.chrome.browser.preferences.DocumentModeManager;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.DocumentModeAssassin;
 import org.chromium.chrome.browser.upgrade.UpgradeActivity;
@@ -63,7 +57,6 @@ import org.chromium.chrome.browser.webapps.WebappLauncherActivity;
 
 import java.lang.ref.WeakReference;
 import java.net.URI;
-import java.util.List;
 import java.util.UUID;
 
 /**
@@ -151,7 +144,6 @@ public class ChromeLauncherActivity extends Activity
         // show homepage, which might require reading PartnerBrowserCustomizations provider.
         PartnerBrowserCustomizations.initializeAsync(getApplicationContext(),
                 PARTNER_BROWSER_CUSTOMIZATIONS_TIMEOUT_MS);
-        maybePerformMigrationTasks();
         recordIntentMetrics();
 
         mIsInLegacyMultiInstanceMode =
@@ -262,18 +254,6 @@ public class ChromeLauncherActivity extends Activity
         }
     }
 
-    /**
-     * If we have just opted in or opted out of document mode, perform pending migration tasks
-     * such as cleaning up the recents.
-     */
-    private void maybePerformMigrationTasks() {
-        if (DocumentModeManager.getInstance(this).isOptOutCleanUpPending()) {
-            cleanUpChromeRecents(
-                    DocumentModeManager.getInstance(this).isOptedOutOfDocumentMode());
-            DocumentModeManager.getInstance(this).setOptOutCleanUpPending(false);
-        }
-    }
-
     @Override
     public void processWebSearchIntent(String query) {
         Intent searchIntent = new Intent(Intent.ACTION_WEB_SEARCH);
@@ -483,31 +463,6 @@ public class ChromeLauncherActivity extends Activity
     }
 
     /**
-     * On opting out, remove all the old tasks from the recents.
-     * @param fromDocument Whether any possible migration was from document mode to classic.
-     */
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    private void cleanUpChromeRecents(boolean fromDocument) {
-        ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
-        List<ActivityManager.AppTask> taskList = am.getAppTasks();
-        PackageManager pm = getPackageManager();
-        for (int i = 0; i < taskList.size(); i++) {
-            AppTask task = taskList.get(i);
-            String className = DocumentUtils.getTaskClassName(task, pm);
-            if (className == null) continue;
-
-            RecentTaskInfo taskInfo = DocumentUtils.getTaskInfoFromTask(task);
-            if (taskInfo == null) continue;
-
-            // Skip the document activities if we are migrating from classic to document.
-            boolean skip = !fromDocument && DocumentActivity.isDocumentActivity(className);
-            if (!skip && (taskInfo.id != getTaskId())) {
-                taskList.get(i).finishAndRemoveTask();
-            }
-        }
-    }
-
-    /**
      * @return Whether there is already an browser instance of Chrome already running.
      */
     public boolean isChromeBrowserActivityRunning() {