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..092ae3a2c4b39bdb69dfb519717b78ff2c5d3f1a 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
@@ -8,6 +8,10 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.AsyncTask;
 
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.CalledByNative;
+
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
@@ -35,10 +39,8 @@ 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;
 
@@ -61,9 +63,7 @@ public class WebappRegistry {
         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
@@ -73,6 +73,36 @@ public class WebappRegistry {
         }.execute();
     }
 
+    /** Deletes the data of all webapps as well as the registry tracking the webapps. */
+    @VisibleForTesting
+    static void unregisterAllWebapps(final Context context) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected final Void doInBackground(Void... nothing) {
+                unregisterAllWebappsInBackground(context);
+                return null;
+            }
+        }.execute();
+    }
+
+    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());
+    }
+
+    @CalledByNative
+    private static void unregisterAllWebappsInBackground(Context context) {
+        assert !ThreadUtils.runningOnUiThread();
+        SharedPreferences preferences = openSharedPreferences(context);
+        for (String id : getRegisteredWebappIds(preferences)) {
+            WebappDataStorage.delete(context, id);
+        }
+        preferences.edit().clear().commit();
+    }
+
     private WebappRegistry() {
     }