Add notification dots and popup menu notification support to the taskbar.

- Added support for notification dots
- Added support for notifications in popup menu
- Added support for dismissing notifications from the popup menu

Bug: 198438631
Test: long pressed launcher and taskbar icons, clicked notifications, clicked shortcuts
Change-Id: I7c981e60a82b4d6ce28332d804bbbfb5eb89c6a8

quickstep/src/com/android/launcher3/taskbar/TaskbarView.java

@@ -36,6 +36,7 @@ import com.android.launcher3.model.data.FolderInfo;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.WorkspaceItemInfo;
 import com.android.launcher3.uioverrides.ApiWrapper;
+import com.android.launcher3.util.LauncherBindableItemsContainer;
 import com.android.launcher3.views.ActivityContext;
 
 /**
@@ -330,4 +331,14 @@ public class TaskbarView extends FrameLayout implements FolderIcon.FolderIconPar
         // Consider the overall visibility
         return getVisibility() == VISIBLE;
     }
+
+    protected void mapOverItems(LauncherBindableItemsContainer.ItemOperator op) {
+        // map over all the shortcuts on the taskbar
+        for (int i = 0; i < getChildCount(); i++) {
+            View item = getChildAt(i);
+            if (op.evaluate((ItemInfo) item.getTag(), item)) {
+                return;
+            }
+        }
+    }
 }