Store standalone web app data in WebappDataStorage as well as the homescreen intent.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java
index 9ef04698f393a7ae27da573c08b4c4e79981fb67..0b9426818b154dad97f2a3ecd948980ec3bca5af 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappRegistry.java
@@ -38,36 +38,75 @@ public class WebappRegistry {
     static final long WEBAPP_UNOPENED_CLEANUP_DURATION = TimeUnit.DAYS.toMillis(13L * 7L);
 
     /**
-     * Called when a retrieval of the stored web apps occurs.
+     * Called when a retrieval of the set of stored web app ids occurs.

[gone, 2016/04/01 23:44:48]

nit: IDs

[dominickn, 2016/04/04 07:26:24]

Done.

      */
     public interface FetchCallback {
         public void onWebappIdsRetrieved(Set<String> readObject);
     }
 
     /**
-     * Registers the existence of a web app and creates the SharedPreference for it.
+     * Called when a retrieval of the stored WebappDataStorage occurs. The storage parameter will
+     * be null if the web app queried for was not in the registry.
+     */
+    public interface FetchWebappDataStorageCallback {
+        public void onWebappDataStorageRetrieved(WebappDataStorage storage);
+    }
+
+    /**
+     * Registers the existence of a web app, creates the SharedPreference for it, and returns the
+     * resulting WebappDataStorage object.
      * @param context  Context to open the registry with.
      * @param webappId The id of the web app to register.
+     * @return The storage object for the web app.
      */
-    public static void registerWebapp(final Context context, final String webappId,
-            final String scope) {
+    public static WebappDataStorage registerWebapp(final Context context, final String webappId) {
+        final WebappDataStorage storage = new WebappDataStorage(context, webappId);
         new AsyncTask<Void, Void, Void>() {
             @Override
             protected final Void doInBackground(Void... nothing) {
                 SharedPreferences preferences = openSharedPreferences(context);
+                // The set returned by getRegisteredWebappIds must be treated as immutable, so we
+                // make a copy to edit and save.
                 Set<String> webapps = new HashSet<String>(getRegisteredWebappIds(preferences));
                 boolean added = webapps.add(webappId);
                 assert added;
 
+                preferences.edit().putStringSet(KEY_WEBAPP_SET, webapps).apply();
+
                 // Update the last used time, so we can guarantee that a web app which appears in
                 // the registry will have a last used time != WebappDataStorage.LAST_USED_INVALID.
-                WebappDataStorage storage = new WebappDataStorage(context, webappId);
-                storage.setScope(scope);
                 storage.updateLastUsedTime();
-                preferences.edit().putStringSet(KEY_WEBAPP_SET, webapps).apply();
                 return null;
             }
         }.execute();
+
+        return storage;
+    }
+
+    /**
+     * Runs the callback, supplying the WebappDataStorage object for webappId, or null if the web
+     * app has not been registered.
+     * @param context  Context to open the registry with.
+     * @param webappId The id of the web app to register.
+     * @return The storage object for the web app, or null if webappId is not registered.
+     */
+    public static void getWebappDataStorage(final Context context, final String webappId,
+            final FetchWebappDataStorageCallback callback) {
+        new AsyncTask<Void, Void, Boolean>() {
+            @Override
+            protected final Boolean doInBackground(Void... nothing) {
+                SharedPreferences preferences = openSharedPreferences(context);
+                return getRegisteredWebappIds(preferences).contains(webappId);
+            }
+
+            protected final void onPostExecute(Boolean exists) {
+                WebappDataStorage storage = null;
+                if (exists) {
+                    storage = WebappDataStorage.open(context, webappId);
+                }
+                callback.onWebappDataStorageRetrieved(storage);
+            }
+        }.execute();
     }
 
     /**