Enable deep-linking from notifications for recently used web apps on the Android home screen.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.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.content.Intent;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.drawable.Drawable;
@@ skipping 246 matching lines @@
                 new WebappRegistry.FetchWebappDataStorageCallback() {
                     @Override
                     public void onWebappDataStorageRetrieved(WebappDataStorage storage) {
                         if (storage == null) return;
 
                         // The information in the WebappDataStorage may have been purged by the
                         // user clearing their history or not launching the web app recently.
                         // Restore the data if necessary from the intent.
                         storage.updateFromShortcutIntent(intent);
 
+                        // A recent last used time is the indicator that the web app is still
+                        // present on the home screen, and enables sources such as notifications to
+                        // launch web apps. Thus, we do not update the last used time when the web
+                        // app is not directly launched from the home screen, as this interferes
+                        // with the heuristic.
+                        if (mWebappInfo.isLaunchedFromHomescreen()) {
+                            storage.updateLastUsedTime();
+                            storage.setLaunched();
+                        }
+
                         // Retrieve the splash image if it exists.
                         storage.getSplashScreenImage(new WebappDataStorage.FetchCallback<Bitmap>() {
                             @Override
                             public void onDataRetrieved(Bitmap splashImage) {
                                 initializeSplashScreenWidgets(backgroundColor, splashImage);
                             }
                         });
                     }
                 }
         );
@@ skipping 307 matching lines @@
         return visible;
     }
 
     // We're temporarily disable CS on webapp since there are some issues. (http://crbug.com/471950)
     // TODO(changwan): re-enable it once the issues are resolved.
     @Override
     protected boolean isContextualSearchAllowed() {
         return false;
     }
 }