Fix: long-tapping a WebAPK in recents shows Chrome.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.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.webapps;
 
 import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Build;
@@ skipping 22 matching lines @@
 public class WebappLauncherActivity extends Activity {
     /**
      * Action fired when an Intent is trying to launch a WebappActivity.
      * Never change the package name or the Intents will fail to launch.
      */
     public static final String ACTION_START_WEBAPP =
             "com.google.android.apps.chrome.webapps.WebappManager.ACTION_START_WEBAPP";
 
     private static final String TAG = "webapps";
 
+    /**
+     * We remove android:documentLaunchMode="intoExisting" attribute from WebApkActivity since this
+     * version.
+     */
+    private static final int SHELL_APK_VERSION_BEFROE_REMOVE_DOCUMENT_LAUNCH_MODE = 1;

[gone, 2017/03/22 22:20:07]

BEFORE

+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         launchActivity();
         ApiCompatibilityUtils.finishAndRemoveTask(this);
     }
 
     public void launchActivity() {
         Intent intent = getIntent();
 
@@ skipping 89 matching lines @@
         // Create an intent to launch the Webapp in an unmapped WebappActivity.
         Intent launchIntent = new Intent();
         launchIntent.setClassName(this, activityName);
         info.setWebappIntentExtras(launchIntent);
 
         // On L+, firing intents with the exact same data should relaunch a particular
         // Activity.
         launchIntent.setAction(Intent.ACTION_VIEW);
         launchIntent.setData(Uri.parse(WebappActivity.WEBAPP_SCHEME + "://" + info.id()));
 
-        if (!isWebApk) {
-            // For WebAPK, we don't start a new task for WebApkActivity, it is just on top
-            // of the WebAPK's main activity and in the same task.
-            launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
-                    | ApiCompatibilityUtils.getActivityNewDocumentFlag());
+        if ((isWebApk && info instanceof WebApkInfo
+                    && ((WebApkInfo) info).shellApkVersion()
+                            > SHELL_APK_VERSION_BEFROE_REMOVE_DOCUMENT_LAUNCH_MODE)
+                || source == ShortcutSource.NOTIFICATION) {
+            // Since shell APK version 2, we removes the android:documentLaunchMode="intoExisting"
+            // attribute from WebApkActivity. Instead, flag {@link FLAG_ACTIVITY_CLEAR_TOP} is used
+            // to deliver this intent to the WebApkActivity instance if it is already running on the
+            // top of the stack via onNewIntent(). WebApkActivity should be on top of the WebAPK's
+            // main activity in the same task stack. See crbug.com/700157.
 
             // If this is launching from a notification, we want to ensure that the URL being
             // launched is the URL in the intent. If a paused WebappActivity exists for this id,
             // then by default it will be focused and we have no way of sending the desired URL to
             // it (the intent is swallowed). As a workaround, set the CLEAR_TOP flag to ensure that
             // the existing Activity is cleared and relaunched with this intent.
             // TODO(dominickn): ideally, we want be able to route an intent to
             // WebappActivity.onNewIntent instead of restarting the Activity.
-            if (source == ShortcutSource.NOTIFICATION) {
-                launchIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
-            }
+            launchIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        } else {

[gone, 2017/03/22 22:20:07]

You've changed this logic here so that non WebApks do either the first half of
the statement or the second half, depending on whether you're doing this from a
notification.  Is that intentional?

[gone, 2017/03/22 22:23:28]

Well, I can see how this would stay the same logically.  The other version was
weirdly written so that it would override the flags from the previous call
instead of using an else clause.

+            launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
+                    | ApiCompatibilityUtils.getActivityNewDocumentFlag());
         }
         return launchIntent;
     }
 
     /**
      * Brings a live WebappActivity back to the foreground if one exists for the given tab ID.
      * @param tabId ID of the Tab to bring back to the foreground.
      * @return True if a live WebappActivity was found, false otherwise.
      */
     public static boolean bringWebappToFront(int tabId) {
@@ skipping 32 matching lines @@
         String url = IntentUtils.safeGetStringExtra(intent, ShortcutHelper.EXTRA_URL);
         if (TextUtils.isEmpty(url)) return false;
 
         if (!webApkPackage.equals(WebApkValidator.queryWebApkPackage(this, url))) {
             Log.d(TAG, "%s is not within scope of %s WebAPK", url, webApkPackage);
             return false;
         }
         return true;
     }
 }