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);
 
+                        // Update the last used time only when the web app has been directly
+                        // launched from home screen.

[gone, 2016/04/07 19:10:44]

nit: Maybe comment here about why?  Not wanting to mess with our heuristics for
guessing about whether something is still on the home screen makes sense for me,
but whoever follows might not understand the nuance.

[dominickn, 2016/04/08 01:10:45]

Done.

+                        if (mWebappInfo.launchedFromHomescreen()) {
+                            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;
     }
 }