Defaulting all downloads to go through Chrome network stack

chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.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.externalnav;
 
 import android.Manifest.permission;
 import android.app.Activity;
 import android.content.Context;
 import android.content.DialogInterface;
@@ skipping 17 matching lines @@
 import org.chromium.base.ApplicationState;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.PathUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.ChromeApplication;
-import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.ChromeTabbedActivity2;
 import org.chromium.chrome.browser.IntentHandler;
 import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.externalnav.ExternalNavigationHandler.OverrideUrlLoadingResult;
 import org.chromium.chrome.browser.instantapps.InstantAppsHandler;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.util.UrlUtilities;
 import org.chromium.chrome.browser.webapps.WebappActivity;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.common.Referrer;
@@ skipping 480 matching lines @@
 
     private void closeTab(Tab tab) {
         Context context = tab.getWindowAndroid().getContext().get();
         if (context instanceof ChromeActivity) {
             ((ChromeActivity) context).getTabModelSelector().closeTab(tab);
         }
     }
 
     @Override
     public boolean isPdfDownload(String url) {
-        if (ChromeFeatureList.isEnabled(ChromeFeatureList.SYSTEM_DOWNLOAD_MANAGER)) return false;
-
         String fileExtension = MimeTypeMap.getFileExtensionFromUrl(url);
         if (TextUtils.isEmpty(fileExtension)) return false;
 
         return PDF_EXTENSION.equals(fileExtension);
     }
 
     @Override
     public void maybeRecordAppHandlersInIntent(Intent intent, List<ResolveInfo> infos) {
         intent.putExtra(IntentHandler.EXTRA_EXTERNAL_NAV_PACKAGES,
                 getSpecializedHandlersWithFilter(infos, null));
     }
 
     @Override
     public boolean maybeLaunchInstantApp(String url, String referrerUrl) {
         return InstantAppsHandler.getInstance((ChromeApplication) mApplicationContext)
                 .handleNavigation(getAvailableContext(), url,
                         TextUtils.isEmpty(referrerUrl) ? null : Uri.parse(referrerUrl));
     }
 }