Fix bug where thumbnails in Recents disappear

Bug: 7900353
Bug: 8752242
Bug: 7382208

packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java

@@ -286,6 +286,10 @@ public class RecentTasksLoader implements View.OnTouchListener {
 
 
     private void cancelLoadingThumbnailsAndIcons() {
+        if (mRecentsPanel != null && mRecentsPanel.isShowing()) {
+            return;
+        }
+
         if (mTaskLoader != null) {
             mTaskLoader.cancel(false);
             mTaskLoader = null;

packages/SystemUI/src/com/android/systemui/recent/RecentsActivity.java

@@ -127,6 +127,9 @@ public class RecentsActivity extends Activity {
         }
         mShowing = true;
         if (mRecentsPanel != null) {
+            // Call and refresh the recent tasks list in case we didn't preload tasks
+            // or in case we don't get an onNewIntent
+            mRecentsPanel.refreshRecentTasksList();
             mRecentsPanel.refreshViews();
         }
         super.onStart();