Store URLs in WebappDataStorage, and purge them when history is cleared.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
index a7fd579268f336d49bf383d1bfee84165fa57f37..103897ee191c9f99401b08bc426c78f3c1eb8551 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
@@ -31,7 +31,13 @@ public class WebappDataStorage {
     static final String SHARED_PREFS_FILE_PREFIX = "webapp_";
     static final String KEY_SPLASH_ICON = "splash_icon";
     static final String KEY_LAST_USED = "last_used";
-    static final long INVALID_LAST_USED = -1;
+    static final String KEY_ORIGIN_URL = "origin_url";
+
+    // Unset/invalid constants for last used times and origins. 0 is used as the null last used time
+    // as WebappRegistry assumes that this is always a valid timestamp.
+    static final long LAST_USED_UNSET = 0;
+    static final long LAST_USED_INVALID = -1;
+    static final String ORIGIN_URL_INVALID = "";
 
     private static Factory sFactory = new Factory();
 
@@ -47,12 +53,12 @@ public class WebappDataStorage {
         new AsyncTask<Void, Void, Void>() {
             @Override
             protected final Void doInBackground(Void... nothing) {
-                if (storage.getLastUsedTime() == INVALID_LAST_USED) {
+                if (storage.getLastUsedTime() == LAST_USED_INVALID) {
                     // If the last used time is invalid then assert that there is no data
                     // in the WebappDataStorage which needs to be cleaned up.
                     assert storage.getAllData().isEmpty();
                 } else {
-                    storage.updateLastUsedTime();
+                    storage.updateLastUsedTime(System.currentTimeMillis());
                 }
                 return null;
             }
@@ -67,6 +73,7 @@ public class WebappDataStorage {
      * @param webappId The ID of the web app the used time is being read for.
      * @param callback Called when the last used time has been retrieved.
      */
+    @VisibleForTesting

[mlamouri (slow - plz ping), 2016/03/16 13:34:28]

Can you remove this? I'm pretty sure it is not visible for testing.

[dominickn, 2016/03/17 04:31:26]

It's used in the ClearBrowsingDataPreferencesTest, so without this
annotation ProGuard strips out the reference and the test crashes
with NoSuchMethodError.

     public static void getLastUsedTime(final Context context, final String webappId,
             final FetchCallback<Long> callback) {
         new AsyncTask<Void, Void, Long>() {
@@ -74,7 +81,7 @@ public class WebappDataStorage {
             protected final Long doInBackground(Void... nothing) {
                 long lastUsed = new WebappDataStorage(context.getApplicationContext(), webappId)
                         .getLastUsedTime();
-                assert lastUsed != INVALID_LAST_USED;
+                assert lastUsed != LAST_USED_INVALID;
                 return lastUsed;
             }
 
@@ -86,6 +93,48 @@ public class WebappDataStorage {
     }
 
     /**
+     * Asynchronously retrieves the origin URL stored in this WebappDataStorage.
+     * @param context  The context to read the SharedPreferences file.
+     * @param webappId The ID of the web app the used time is being read for.
+     * @param callback Called when the origin has been retrieved.
+     */
+    @VisibleForTesting
+    public static void getOriginUrl(final Context context, final String webappId,
+            final FetchCallback<String> callback) {
+        new AsyncTask<Void, Void, String>() {
+            @Override
+            protected final String doInBackground(Void... nothing) {
+                String originUrl = new WebappDataStorage(context.getApplicationContext(), webappId)
+                        .getOriginUrl();
+                return originUrl;
+            }
+
+            @Override
+            protected final void onPostExecute(String originUrl) {
+                callback.onDataRetrieved(originUrl);
+            }
+        }.execute();
+    }
+
+    /**
+     * Asynchronously updates the origin URL stored in this WebappDataStorage.
+     * @param context  The context to read the SharedPreferences file.
+     * @param webappId The ID of the web app the used time is being read for.
+     * @param origin The origin to set for the web app.
+     */
+    public static void updateOriginUrl(final Context context, final String webappId,
+            final String originUrl) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected final Void doInBackground(Void... nothing) {
+                new WebappDataStorage(context.getApplicationContext(), webappId)
+                        .updateOriginUrl(originUrl);
+                return null;
+            }
+        }.execute();
+    }
+
+    /**
      * Deletes the data for a web app by clearing all the information inside the SharedPreferences
      * file. This does NOT delete the file itself but the file is left empty.
      * @param context  The context to read the SharedPreferences file.
@@ -97,6 +146,21 @@ public class WebappDataStorage {
     }
 
     /**
+     * Deletes the origin URL and sets last used time to 0 this web app in SharedPreferences.
+     * This does not remove the stored splash screen image (if any) for the app.

[mlamouri (slow - plz ping), 2016/03/16 13:34:28]

Deleting the origin sounds odd as in not really related to history and might
give a false impression of privacy (ie. the splashscreen image might still
reveals the website). Though I guess it's a requirement from privacy.

[dominickn, 2016/03/17 04:31:26]

I guess the combination of having a last used time and an origin gives you
history information. :)

[mlamouri (slow - plz ping), 2016/03/24 10:36:42]

Sure. What I meant is that the splashscreen image wil likely leak the origin.

+     * @param context  The context to read the SharedPreferences file.
+     * @param webappId The ID of the web app being deleted.
+     */
+    static void clearHistory(final Context context, final String webappId) {
+        // The last used time is set to 0 to ensure that a valid value is always present.
+        // If the webapp is not launched prior to the next cleanup, then its remaining data will be
+        // removed. Otherwise, the next launch will update the last used time.
+        assert !ThreadUtils.runningOnUiThread();
+        openSharedPreferences(context, webappId)
+                .edit().putLong(KEY_LAST_USED, LAST_USED_UNSET).remove(KEY_ORIGIN_URL).apply();
+    }
+
+    /**
      * Sets the factory used to generate WebappDataStorage objects.
      */
     @VisibleForTesting
@@ -119,26 +183,70 @@ public class WebappDataStorage {
      * @param callback Called when the splash screen image has been retrieved.
      *                 May be null if no image was found.
      */
-    public void getSplashScreenImage(FetchCallback<Bitmap> callback) {
-        new BitmapFetchTask(KEY_SPLASH_ICON, callback).execute();
+    public void getSplashScreenImage(final FetchCallback<Bitmap> callback) {
+        new AsyncTask<Void, Void, Bitmap>() {
+            @Override
+            protected final Bitmap doInBackground(Void... nothing) {
+                return ShortcutHelper.decodeBitmapFromString(
+                        mPreferences.getString(KEY_SPLASH_ICON, null));
+            }
+
+            @Override
+            protected final void onPostExecute(Bitmap result) {
+                callback.onDataRetrieved(result);
+            }
+        }.execute();
     }
 
     /*
      * Update the information associated with the web app with the specified data.
      * @param splashScreenImage The image which should be shown on the splash screen of the web app.
      */
-    public void updateSplashScreenImage(Bitmap splashScreenImage) {
-        new UpdateTask(splashScreenImage).execute();
+    public void updateSplashScreenImage(final Bitmap splashScreenImage) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected final Void doInBackground(Void... nothing) {
+                mPreferences.edit()
+                        .putString(KEY_SPLASH_ICON,
+                                ShortcutHelper.encodeBitmapAsString(splashScreenImage))
+                        .apply();
+                return null;
+            }
+        }.execute();
     }
 
-    void updateLastUsedTime() {
+    /**
+     * Updates the origin URL stored in this object.
+     * @param originUrl the new origin URL
+     */
+    void updateOriginUrl(String originUrl) {
+        assert !ThreadUtils.runningOnUiThread();
+        mPreferences.edit().putString(KEY_ORIGIN_URL, originUrl).apply();
+    }
+
+    /**
+     * Returns the origin URL stored in this object, or "" if it is not stored.
+     */
+    String getOriginUrl() {
+        assert !ThreadUtils.runningOnUiThread();
+        return mPreferences.getString(KEY_ORIGIN_URL, ORIGIN_URL_INVALID);
+    }
+
+    /**
+     * Updates the last used time of this object.
+     * @param lastUsedTime the new last used time.
+     */
+    void updateLastUsedTime(long lastUsedTime) {

[mlamouri (slow - plz ping), 2016/03/16 13:34:28]

Did you consider updateLastUsedTime() and resetLastUsedTime()? Actually, I can't
see a usage with updateLastUsedTime() that takes something else than current
time.

[dominickn, 2016/03/17 04:31:26]

Originally, the reset method used this mechanism, but now it doesn't.
Refactored.

         assert !ThreadUtils.runningOnUiThread();
-        mPreferences.edit().putLong(KEY_LAST_USED, System.currentTimeMillis()).apply();
+        mPreferences.edit().putLong(KEY_LAST_USED, lastUsedTime).apply();
     }
 
+    /**
+     * Returns the last used time of this object, or -1 if it is not stored.
+     */
     long getLastUsedTime() {
         assert !ThreadUtils.runningOnUiThread();
-        return mPreferences.getLong(KEY_LAST_USED, INVALID_LAST_USED);
+        return mPreferences.getLong(KEY_LAST_USED, LAST_USED_INVALID);
     }
 
     private Map<String, ?> getAllData() {
@@ -166,42 +274,4 @@ public class WebappDataStorage {
             return new WebappDataStorage(context, webappId);
         }
     }
-
-    private final class BitmapFetchTask extends AsyncTask<Void, Void, Bitmap> {
-
-        private final String mKey;
-        private final FetchCallback<Bitmap> mCallback;
-
-        public BitmapFetchTask(String key, FetchCallback<Bitmap> callback) {
-            mKey = key;
-            mCallback = callback;
-        }
-
-        @Override
-        protected final Bitmap doInBackground(Void... nothing) {
-            return ShortcutHelper.decodeBitmapFromString(mPreferences.getString(mKey, null));
-        }
-
-        @Override
-        protected final void onPostExecute(Bitmap result) {
-            mCallback.onDataRetrieved(result);
-        }
-    }
-
-    private final class UpdateTask extends AsyncTask<Void, Void, Void> {
-
-        private final Bitmap mSplashImage;
-
-        public UpdateTask(Bitmap splashImage) {
-            mSplashImage = splashImage;
-        }
-
-        @Override
-        protected Void doInBackground(Void... nothing) {
-            mPreferences.edit()
-                    .putString(KEY_SPLASH_ICON, ShortcutHelper.encodeBitmapAsString(mSplashImage))
-                    .apply();
-            return null;
-        }
-    }
-}
+}