Clear webapp storage when site data is cleared

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 fe19baaa4b8a989dac549b7ba1c400cbc802d928..dff54ad1e36ae6b3c2f3b12acefbf6d0b55b8a11 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
@@ -8,12 +8,15 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.AsyncTask;
 
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.CalledByNative;
+
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
 /**
- * Keeps track of webapps which have created a SharedPreference file (through the used of the
+ * Keeps track of web apps which have created a SharedPreference file (through the used of the
  * WebappDataStorage class) which may need to be cleaned up in the future.
  *
  * It is NOT intended to be 100% accurate nor a comprehensive list of all installed web apps
@@ -27,6 +30,13 @@ public class WebappRegistry {
     static final String KEY_WEBAPP_SET = "webapp_set";
 
     /**
+     * Called when a retrieval of the stored web apps occurs.
+     */
+    public interface FetchCallback {
+        public void onWebappIdsRetrieved(Set<String> readObject);
+    }
+
+    /**
      * Registers the existence of a web app and creates the SharedPreference for it.
      * @param context  Context to open the registry with.
      * @param webappId The id of the web app to register.
@@ -35,16 +45,14 @@ public class WebappRegistry {
         new AsyncTask<Void, Void, Void>() {
             @Override
             protected final Void doInBackground(Void... nothing) {
-                SharedPreferences preferences = context.getSharedPreferences(
-                        REGISTRY_FILE_NAME, Context.MODE_PRIVATE);
-                Set<String> webapps = new HashSet<String>(
-                        preferences.getStringSet(KEY_WEBAPP_SET, Collections.<String>emptySet()));
+                SharedPreferences preferences = openSharedPreferences(context);
+                Set<String> webapps = new HashSet<String>(getRegisteredWebappIds(preferences));
                 boolean added = webapps.add(webappId);
                 assert added;
 
-                // Update the last used time of the webapp data storage so we can guarantee that
-                // the used time will be set (ie. != WebappDataStorage.INVALID_LAST_USED) if a
-                // webapp appears in the registry.
+                // Update the last used time of the {@link WebappDataStorage} so we can guarantee
+                // that the used time will be set (ie. != WebappDataStorage.INVALID_LAST_USED) if a
+                // web app appears in the registry.
                 new WebappDataStorage(context, webappId).updateLastUsedTime();
                 preferences.edit().putStringSet(KEY_WEBAPP_SET, webapps).commit();
                 return null;
@@ -57,13 +65,12 @@ public class WebappRegistry {
      * @param context  Context to open the registry with.
      * @param callback Called when the set has been retrieved. The set may be empty.
      */
+    @VisibleForTesting
     public static void getRegisteredWebappIds(final Context context, final FetchCallback callback) {
         new AsyncTask<Void, Void, Set<String>>() {
             @Override
             protected final Set<String> doInBackground(Void... nothing) {
-                SharedPreferences preferences = context.getSharedPreferences(
-                        REGISTRY_FILE_NAME, Context.MODE_PRIVATE);
-                return preferences.getStringSet(KEY_WEBAPP_SET, Collections.<String>emptySet());
+                return getRegisteredWebappIds(openSharedPreferences(context));
             }
 
             @Override
@@ -73,13 +80,50 @@ public class WebappRegistry {
         }.execute();
     }
 
-    private WebappRegistry() {
-    }
-
     /**
-     * Called when a retrieval of the stored web apps occurs.
+     * Deletes the data of all web apps, as well as the registry tracking the web apps.
      */
-    public interface FetchCallback {
-        public void onWebappIdsRetrieved(Set<String> readObject);
+    @VisibleForTesting
+    static void unregisterAllWebapps(final Context context, final Runnable callback) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected final Void doInBackground(Void... nothing) {
+                SharedPreferences preferences = openSharedPreferences(context);
+                for (String id : getRegisteredWebappIds(preferences)) {
+                    WebappDataStorage.deleteDataForWebapp(context, id);
+                }
+                preferences.edit().clear().commit();
+                return null;
+            }
+
+            @Override
+            protected final void onPostExecute(Void nothing) {
+                if (callback == null) return;
+                callback.run();
+            }
+        }.execute();
+    }
+
+    @CalledByNative
+    static void unregisterAllWebapps(Context context, final long callbackPointer) {
+        unregisterAllWebapps(context, new Runnable() {
+            @Override
+            public void run() {
+                nativeOnWebappsUnregistered(callbackPointer);
+            }
+        });
     }
+
+    private static SharedPreferences openSharedPreferences(Context context) {
+        return context.getSharedPreferences(REGISTRY_FILE_NAME, Context.MODE_PRIVATE);
+    }
+
+    private static Set<String> getRegisteredWebappIds(SharedPreferences preferences) {
+        return preferences.getStringSet(KEY_WEBAPP_SET, Collections.<String>emptySet());
+    }
+
+    private WebappRegistry() {
+    }
+
+    private static native void nativeOnWebappsUnregistered(long callbackPointer);
 }