Remove all deferred widget pages when we cancel all tasks. (Potential fix for bug 6387680)

Change-Id: I65ad089ff20daffdc8ba09d975ac31e87965a4a7
diff --git a/src/com/android/launcher2/AppsCustomizePagedView.java b/src/com/android/launcher2/AppsCustomizePagedView.java
index 2935cea..895d4dd 100644
--- a/src/com/android/launcher2/AppsCustomizePagedView.java
+++ b/src/com/android/launcher2/AppsCustomizePagedView.java
@@ -859,6 +859,7 @@
             iter.remove();
             mDirtyPageContent.set(task.page, true);
         }
+        mDeferredSyncWidgetPageItems.clear();
     }
 
     public void setContentType(ContentType type) {