webapps: Add cleanup task when opening up WebappActivity to clean old web apps

chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java

Index: chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java
index 073e24bcb7e0eacededf84b348b0c6670987dd01..f6ee29c20e9c4fe7e972d83a561efa308ea9e426 100644
--- a/chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java
+++ b/chrome/android/junit/src/org/chromium/chrome/browser/webapps/WebappRegistryTest.java
@@ -9,6 +9,7 @@ import static org.junit.Assert.assertTrue;
 
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.os.SystemClock;
 
 import org.chromium.base.test.util.Feature;
 import org.chromium.testing.local.BackgroundShadowAsyncTask;
@@ -184,6 +185,89 @@ public class WebappRegistryTest {
         assertTrue(actual.isEmpty());
     }
 
+    @Test
+    @Feature({"Webapp"})
+    public void testCleanupDoesNotRunTooOften() throws Exception {
+        // Set the system clock to just before the task should run.
+        SystemClock.setCurrentTimeMillis(WebappRegistry.FULL_CLEANUP_DURATION - 1);

[gone, 2015/09/24 10:27:12]

instead of mucking about with the clock, add some way of passing in the time
when the WebappRegistry needs it.  example of why mucking about with system
settings is bad: you don't reset it at the end of the test, and I don't know if
Robolectric handles that for you.

[Lalit Maganti, 2015/09/24 12:35:44]

Done.

+
+        addWebappsToRegistry("test");

[gone, 2015/09/24 10:27:12]

nit: can you use something other than "test"?  it's too generic.

[Lalit Maganti, 2015/09/24 12:35:44]

Done.

+        SharedPreferences webAppPrefs = Robolectric.application.getSharedPreferences(
+                WebappDataStorage.SHARED_PREFS_FILE_PREFIX + "test", Context.MODE_PRIVATE);
+        webAppPrefs.edit()
+                .putLong(WebappDataStorage.KEY_LAST_USED, Long.MIN_VALUE)
+                .commit();
+
+        WebappRegistry.unregisterOldWebapps(Robolectric.application);
+        BackgroundShadowAsyncTask.runBackgroundTasks();
+
+        Set<String> actual = mSharedPreferences.getStringSet(
+                WebappRegistry.KEY_WEBAPP_SET, Collections.<String>emptySet());
+        assertEquals(new HashSet<String>(Arrays.asList("test")), actual);
+
+        long actualLastUsed = webAppPrefs.getLong(WebappDataStorage.KEY_LAST_USED,
+                WebappDataStorage.INVALID_LAST_USED);
+        assertEquals(Long.MIN_VALUE, actualLastUsed);
+    }
+
+    @Test
+    @Feature({"Webapp"})
+    public void testCleanupDoesNotRemoveRecentApps() throws Exception {
+        // Set the system clock to just before the task should run.
+        SystemClock.setCurrentTimeMillis(WebappRegistry.FULL_CLEANUP_DURATION);
+
+        addWebappsToRegistry("test");
+        SharedPreferences webAppPrefs = Robolectric.application.getSharedPreferences(
+                WebappDataStorage.SHARED_PREFS_FILE_PREFIX + "test", Context.MODE_PRIVATE);
+
+        // Put the last used time just inside the no-cleanup window.
+        long lastUsed =
+                System.currentTimeMillis() - WebappRegistry.WEBAPP_NON_OPEN_CLEANUP_DURATION + 1;
+        webAppPrefs.edit()
+                .putLong(WebappDataStorage.KEY_LAST_USED, lastUsed)
+                .commit();
+
+        WebappRegistry.unregisterOldWebapps(Robolectric.application);
+        BackgroundShadowAsyncTask.runBackgroundTasks();
+
+        Set<String> actual = mSharedPreferences.getStringSet(
+                WebappRegistry.KEY_WEBAPP_SET, Collections.<String>emptySet());
+        assertEquals(new HashSet<String>(Arrays.asList("test")), actual);
+
+        long actualLastUsed = webAppPrefs.getLong(WebappDataStorage.KEY_LAST_USED,
+                WebappDataStorage.INVALID_LAST_USED);
+        assertEquals(lastUsed, actualLastUsed);
+    }
+
+    @Test
+    @Feature({"Webapp"})
+    public void testCleanupRemovesOldApps() throws Exception {
+        // Set the system clock to just before the task should run.
+        SystemClock.setCurrentTimeMillis(WebappRegistry.FULL_CLEANUP_DURATION);
+
+        addWebappsToRegistry("test");
+        SharedPreferences webAppPrefs = Robolectric.application.getSharedPreferences(
+                WebappDataStorage.SHARED_PREFS_FILE_PREFIX + "test", Context.MODE_PRIVATE);
+
+        // Put the last used time just outside the no-cleanup window.
+        long lastUsed = System.currentTimeMillis()
+                - WebappRegistry.WEBAPP_NON_OPEN_CLEANUP_DURATION;
+        webAppPrefs.edit()
+                .putLong(WebappDataStorage.KEY_LAST_USED, lastUsed)
+                .commit();
+
+        WebappRegistry.unregisterOldWebapps(Robolectric.application);
+        BackgroundShadowAsyncTask.runBackgroundTasks();
+
+        Set<String> actual = mSharedPreferences.getStringSet(
+                WebappRegistry.KEY_WEBAPP_SET, Collections.<String>emptySet());
+        assertTrue(actual.isEmpty());
+
+        long actualLastUsed = webAppPrefs.getLong(WebappDataStorage.KEY_LAST_USED,
+                WebappDataStorage.INVALID_LAST_USED);
+        assertEquals(WebappDataStorage.INVALID_LAST_USED, actualLastUsed);
+    }
+
     private Set<String> addWebappsToRegistry(String... webapps) {
         final Set<String> expected = new HashSet<String>(Arrays.asList(webapps));
         mSharedPreferences.edit()