Fixes redirects to external apps when navigating from PWA.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappTabDelegate.java

 // Copyright 2017 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.webapps;
 
+import android.content.Intent;
 import android.net.Uri;
 import android.support.customtabs.CustomTabsIntent;
 
+import org.chromium.chrome.browser.IntentHandler;
+import org.chromium.chrome.browser.customtabs.CustomTabIntentDataProvider;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabIdManager;
 import org.chromium.chrome.browser.tabmodel.AsyncTabParamsManager;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
 import org.chromium.chrome.browser.tabmodel.document.AsyncTabCreationParams;
 import org.chromium.chrome.browser.tabmodel.document.TabDelegate;
 
 /**
  * Asynchronously creates Tabs for navigation originating from an installed PWA.
  *
  * This is the same as the parent class with exception of opening a Custom Tab for
  * {@code _blank} links and {@code window.open(url)} calls instead of creating a new tab in Chrome.
  */
 public class WebappTabDelegate extends TabDelegate {
-    private final WebappActivity mActivity;
-
-    public WebappTabDelegate(WebappActivity activity, boolean incognito) {
+    public WebappTabDelegate(boolean incognito) {
         super(incognito);
-        this.mActivity = activity;
     }
 
     @Override
     public void createNewTab(AsyncTabCreationParams asyncParams, TabLaunchType type, int parentId) {
         int assignedTabId = TabIdManager.getInstance().generateValidId(Tab.INVALID_TAB_ID);
         AsyncTabParamsManager.add(assignedTabId, asyncParams);
 
-        CustomTabsIntent customTabIntent =
-                new CustomTabsIntent.Builder().setShowTitle(true).build();
+        Intent intent = new CustomTabsIntent.Builder().setShowTitle(true).build().intent;
+        intent.setData(Uri.parse(asyncParams.getLoadUrlParams().getUrl()));
+        intent.putExtra(CustomTabIntentDataProvider.EXTRA_SEND_TO_EXTERNAL_DEFAULT_HANDLER, true);

[Yusuf, 2017/07/07 20:50:02]

Good investigation finding out about this!

I am still a bit confused about your CL description. So the flow was working
even without this but was longer with more transitions? If that is the case we
are hitting a code path that I am not aware of. Since basically AFAIK if you
need this extra, without it things should simply wouldn't work. (Maybe it is
because we are still in Chrome and our internal intent handling eventually takes
care of this but takes more hops to do so?)

[piotrs, 2017/07/09 23:43:38]

My patch description wasn't clear enough, I updated it.

TL;DR
Previously: Redirecting to external apps didn't work.
Now: Redirecting to external apps works, but CCT shows up for a noticeable
amount of time.

I will be looking into how to make ExternalNavigationHandler run sooner in CCT,
same as it does in ChromeTabbedActivity. Any help here would be appreciated BTW.

+        intent.putExtra(CustomTabIntentDataProvider.EXTRA_IS_OPENED_BY_CHROME, true);
+        addAsyncTabExtras(asyncParams, parentId, false /* isChromeUI */, assignedTabId, intent);
 
-        customTabIntent.intent.setPackage(mActivity.getPackageName());
-        addAsyncTabExtras(asyncParams, parentId, true, assignedTabId, customTabIntent.intent);
-        customTabIntent.launchUrl(mActivity, Uri.parse(asyncParams.getLoadUrlParams().getUrl()));
+        IntentHandler.startActivityForTrustedIntent(intent);
     }
 }