Dismissing of docked stack by dragging to the side.

Bug: 24623909
Change-Id: Ic93b169442de1eb4dca9f65a87ae2b813bcef043
diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index 42888cf..faa3a43 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -2691,6 +2691,13 @@
             reply.writeNoException();
             return true;
         }
+        case REMOVE_STACK: {
+            data.enforceInterface(IActivityManager.descriptor);
+            final int stackId = data.readInt();
+            removeStack(stackId);
+            reply.writeNoException();
+            return true;
+        }
         }
 
         return super.onTransact(code, data, reply, flags);
@@ -6239,5 +6246,17 @@
         reply.recycle();
     }
 
+    @Override
+    public void removeStack(int stackId) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeInt(stackId);
+        mRemote.transact(REMOVE_STACK, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
+
     private IBinder mRemote;
 }