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

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
index dc5a805a3e0244c2be00270695f875962b074d40..6d29edc08542bacdac4072b789ddd10f4bf4b3b6 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
@@ -264,6 +264,13 @@ public class WebappActivity extends FullScreenActivity {
                         // 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