Steps to reproduce the problem:
1. App's an activity using webView loads an URL which has javascript popup. And App didn't override onJsConfirm(). and This App is SingleTask operation as declare AndroidManifest.xml android:launchMode="singleTask"
2. There is no problem, user select some action about popup, for example, click "yes" or "no", or touch backKey dismiss popup. 
3. But, if user just press "Home Button" with floating popup,
and then, user enter the app again, this app starts with initial activity. Because, this is singleTask laucnMode app.
4. Finally, retry activity using webview loads URL of step1,
the window is not response, 

The key point is two.
1st, this app is singleTask launchMode app.
2nd, User press home button without any action about javascript  popup.

What is the expected behavior?
Basically, occurs following Exception. But I think WindowManager or WebView can handle this. 
When I tried several ways, but I can't resolve..clearly.

What went wrong?
E/WindowManager: android.view.WindowLeaked: Activity testActivity has leaked window DecorView@1cfb7c9[] that was originally added here
                                                                      at android.view.ViewRootImpl.<init>(ViewRootImpl.java:431)
                                                                      at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:331)
                                                                      at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:94)
                                                                      at android.app.Dialog.show(Dialog.java:337)
                                                                      at android.app.AlertDialog$Builder.show(AlertDialog.java:1213)
                                                                      at android.webkit.JsDialogHelper.showDialog(JsDialogHelper.java:128)
                                                                      at com.android.webview.chromium.WebViewContentsClientAdapter.showDefaultJsDialog(WebViewContentsClientAdapter.java:910)
                                                                      at com.android.webview.chromium.WebViewContentsClientAdapter.handleJsConfirm(WebViewContentsClientAdapter.java:863)
                                                                      at org.chromium.android_webview.AwContentsClientBridge.handleJsConfirm(AwContentsClientBridge.java:239)
                                                                      at org.chromium.base.SystemMessageHandler.nativeDoRunLoopOnce(Native Method)
                                                                      at org.chromium.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:41)
                                                                      at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                      at android.os.Looper.loop(Looper.java:154)
                                                                      at android.app.ActivityThread.main(ActivityThread.java:6316)
                                                                      at java.lang.reflect.Method.invoke(Native Method)

WebStore page: just test app

Did this work before? No 

Chrome version: 56.0.2924.87  Channel: n/a
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: