Allow custom content to lock the workspace

Change-Id: Ic337df1b2cd54b99d4ef02dcfaca955c90297df0
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index a85b5b1..400cd24 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -1089,6 +1089,9 @@
 
         // Custom content scroll progress changed. From 0 (not showing) to 1 (fully showing).
         public void onScrollProgressChanged(float progress);
+
+        // Indicates whether the user is allowed to scroll away from the custom content.
+        boolean isScrollingAllowed();
     }
 
     protected boolean hasSettings() {