Add handler on dialog box open

This handler will listen out for when dialog boxes are opened. When
a CDP event is received for a dialog box opening, we will
automatically dismiss it. This is the first step in dealing with
dialog boxes.

Author: ankur22

common/frame_session.go

@@ -259,12 +259,25 @@ func (fs *FrameSession) initEvents() {
 					fs.onAttachedToTarget(ev)
 				case *target.EventDetachedFromTarget:
 					fs.onDetachedFromTarget(ev)
+				case *cdppage.EventJavascriptDialogOpening:
+					fs.onEventJavascriptDialogOpening(ev)
 				}
 			}
 		}
 	}()
 }
 
+func (fs *FrameSession) onEventJavascriptDialogOpening(event *cdppage.EventJavascriptDialogOpening) {
+	fs.logger.Debugf("FrameSession:onEventJavascriptDialogOpening",
+		"sid:%v tid:%v url:%v dialogType:%s",
+		fs.session.ID(), fs.targetID, event.URL, event.Type)
+
+	action := cdppage.HandleJavaScriptDialog(false)
+	if err := action.Do(cdp.WithExecutor(fs.ctx, fs.session)); err != nil {
+		fs.logger.Errorf("FrameSession:onEventJavascriptDialogOpening", "failed to dismiss dialog box: %v", err)
+	}
+}
+
 func (fs *FrameSession) initFrameTree() error {
 	fs.logger.Debugf("NewFrameSession:initFrameTree",
 		"sid:%v tid:%v", fs.session.ID(), fs.targetID)