Ensure we dismiss the <select> option dialog.

When the WebView is paused, or another action (such as navigating to
a new URL) occurs, cancel any ongoing <select> tag dialog that is open.

Bug: 5666545
Change-Id: Ifc35a239b729ed93cbf82b2096334f7d63f8993d

core/java/android/webkit/WebView.java

@@ -1628,6 +1628,14 @@ public class WebView extends AbsoluteLayout
         clearTextEntry();
         clearActionModes();
         dismissFullScreenMode();
+        cancelSelectDialog();
+    }
+
+    private void cancelSelectDialog() {
+        if (mListBoxDialog != null) {
+            mListBoxDialog.cancel();
+            mListBoxDialog = null;
+        }
     }
 
     /**
@@ -3279,6 +3287,8 @@ public class WebView extends AbsoluteLayout
             if (mNativeClass != 0) {
                 nativeSetPauseDrawing(mNativeClass, true);
             }
+
+            cancelSelectDialog();
         }
     }