Prevent serialization after being destroyed

 Bug: 5246900

Change-Id: Ic0be139b26e1b52203b8d0286c12175df6a1a46c
diff --git a/core/java/android/webkit/ViewStateSerializer.java b/core/java/android/webkit/ViewStateSerializer.java
index 0fc76fa..5f91ed3 100644
--- a/core/java/android/webkit/ViewStateSerializer.java
+++ b/core/java/android/webkit/ViewStateSerializer.java
@@ -36,11 +36,15 @@
 
     static boolean serializeViewState(OutputStream stream, WebView web)
             throws IOException {
+        int baseLayer = web.getBaseLayer();
+        if (baseLayer == 0) {
+            return false;
+        }
         DataOutputStream dos = new DataOutputStream(stream);
         dos.writeInt(VERSION);
         dos.writeInt(web.getContentWidth());
         dos.writeInt(web.getContentHeight());
-        return nativeSerializeViewState(web.getBaseLayer(), dos,
+        return nativeSerializeViewState(baseLayer, dos,
                 new byte[WORKING_STREAM_STORAGE]);
     }
 
diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index 5200b12..230234a 100644
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -4311,6 +4311,9 @@
     }
 
     int getBaseLayer() {
+        if (mNativeClass == 0) {
+            return 0;
+        }
         return nativeGetBaseLayer();
     }