on ad closed getting this error

[imyogisingh]

D/AudioManager( 4439): getStreamVolume isRestricted mode = 0
V/MediaPlayer( 4439): resetDrmState: mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer( 4439): cleanDrmObj: mDrmObj=null mDrmSessionId=null
W/ContentCatcher( 4439): Failed to notify a WebView
W/cr_AwContents( 4439): Application attempted to call on a destroyed WebView
W/cr_AwContents( 4439): java.lang.Throwable
W/cr_AwContents( 4439): at org.chromium.android_webview.AwContents.r(Unknown Source:12)
W/cr_AwContents( 4439): at Ab.loadingStateChanged(Unknown Source:5)
W/cr_AwContents( 4439): at android.os.MessageQueue.nativePollOnce(Native Method)
W/cr_AwContents( 4439): at android.os.MessageQueue.next(MessageQueue.java:336)
W/cr_AwContents( 4439): at android.os.Looper.loop(Looper.java:181)
W/cr_AwContents( 4439): at android.app.ActivityThread.main(ActivityThread.java:7562)
W/cr_AwContents( 4439): at java.lang.reflect.Method.invoke(Native Method)
W/cr_AwContents( 4439): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
W/cr_AwContents( 4439): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)