Add fix to prevent iframe panic on navigation

The change prevents the iframe child frames from being removed when a
detach event comes in from Chrome.

An iframe seems to be associated to multiple sessions. The initial
sessions that is linked to the mainframe that the iframe belongs to and
its own session. When the page navigates, a detach event arrives with
the initial session and a swap type for the iframe. The iframe though
is associated to its own session. In this scenario we want to avoid
removing frames, which prevents panics occurring when the iframe
navigates.

common/frame_manager.go

@@ -173,6 +173,24 @@ func (m *FrameManager) frameDetached(frameID cdp.FrameID, reason cdppage.FrameDe
 		return
 	}
 
+	// This helps prevent an iframe and its child frames from being removed
+	// when the type of detach is a swap. After this detach event usually
+	// the iframe navigates, which requires the frames to be present for the
+	// navigate to work.
+	fs := m.page.getFrameSession(frameID)
+	if fs != nil {
+		m.logger.Debugf("FrameManager:frameDetached:sessionFound",
+			"fmid:%d fid:%v fsID1:%v fsID2:%v found session for frame",
+			m.ID(), frameID, fs.session.ID(), m.session.ID())
+
+		if fs.session.ID() != m.session.ID() {
+			m.logger.Debugf("FrameManager:frameDetached:notSameSession:return",
+				"fmid:%d fid:%v event session and frame session do not match",
+				m.ID(), frameID)
+			return
+		}
+	}
+
 	if reason == cdppage.FrameDetachedReasonSwap {
 		// When a local frame is swapped out for a remote
 		// frame, we want to keep the current frame which is