✈ 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 426c1b5808e65162a4d13d741c9292a12cf4f5c6..84dd7e6dbc512a9618a494c0863cf90455d29352 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
@@ -60,7 +60,6 @@ import org.chromium.chrome.browser.notifications.NotificationPlatformBridge;
 import org.chromium.chrome.browser.partnercustomizations.HomepageManager;
 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.tab.TabIdManager;
 import org.chromium.chrome.browser.tabmodel.AsyncTabParamsManager;
@@ -80,7 +79,6 @@ import org.chromium.ui.base.PageTransition;
 
 import java.lang.ref.WeakReference;
 import java.net.URI;
-import java.util.List;
 import java.util.UUID;
 
 /**
@@ -171,7 +169,6 @@ public class ChromeLauncherActivity extends Activity
         // show homepage, which might require reading PartnerBrowserCustomizations provider.
         PartnerBrowserCustomizations.initializeAsync(getApplicationContext(),
                 PARTNER_BROWSER_CUSTOMIZATIONS_TIMEOUT_MS);
-        maybePerformMigrationTasks();
         recordIntentMetrics();
 
         mIsInLegacyMultiInstanceMode =
@@ -279,18 +276,6 @@ 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);
@@ -890,31 +875,6 @@ 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();
-            }
-        }
-    }
-
-    /**
      * Set flags that ensure that we control when our Activities disappear from Recents.
      * @param intent Intent to set the flags on.
      * @param extraFlags Other flags to add to the Intent, 0 if there's nothing to add.