Use the msgId defined in connection in session

The last piece of the puzzle in ensuring that all msgIds are unique at
the connection scope level is to ensure that same msgId type is used
in the session that is associated to the connection.

common/connection.go

@@ -329,7 +329,7 @@ func (c *Connection) recvLoop() {
 			sid, tid := eva.SessionID, eva.TargetInfo.TargetID
 
 			c.sessionsMu.Lock()
-			session := NewSession(c.ctx, c, sid, tid, c.logger)
+			session := NewSession(c.ctx, c, sid, tid, c.logger, c.msgID)
 			c.logger.Debugf("Connection:recvLoop:EventAttachedToTarget", "sid:%v tid:%v wsURL:%q", sid, tid, c.wsURL)
 			c.sessions[sid] = session
 			c.sessionsMu.Unlock()

common/session.go

@@ -3,7 +3,6 @@ package common
 import (
 	"context"
 	"errors"
-	"sync/atomic"
 
 	"github.com/chromedp/cdproto"
 	"github.com/chromedp/cdproto/cdp"
@@ -24,7 +23,7 @@ type Session struct {
 	conn     *Connection
 	id       target.SessionID
 	targetID target.ID
-	msgID    int64
+	msgID    *msgID
 	readCh   chan *cdproto.Message
 	done     chan struct{}
 	closed   bool
@@ -35,7 +34,7 @@ type Session struct {
 
 // NewSession creates a new session.
 func NewSession(
-	ctx context.Context, conn *Connection, id target.SessionID, tid target.ID, logger *log.Logger,
+	ctx context.Context, conn *Connection, id target.SessionID, tid target.ID, logger *log.Logger, msgID *msgID,
 ) *Session {
 	s := Session{
 		BaseEventEmitter: NewBaseEventEmitter(ctx),
@@ -44,6 +43,7 @@ func NewSession(
 		targetID:         tid,
 		readCh:           make(chan *cdproto.Message),
 		done:             make(chan struct{}),
+		msgID:            msgID,
 
 		logger: logger,
 	}
@@ -118,7 +118,7 @@ func (s *Session) Execute(ctx context.Context, method string, params easyjson.Ma
 		return ErrTargetCrashed
 	}
 
-	id := atomic.AddInt64(&s.msgID, 1)
+	id := s.msgID.new()
 
 	// Setup event handler used to block for response to message being sent.
 	ch := make(chan *cdproto.Message, 1)
@@ -186,7 +186,7 @@ func (s *Session) ExecuteWithoutExpectationOnReply(ctx context.Context, method s
 		}
 	}
 	msg := &cdproto.Message{
-		ID: atomic.AddInt64(&s.msgID, 1),
+		ID: s.msgID.new(),
 		// We use different sessions to send messages to "targets"
 		// (browser, page, frame etc.) in CDP.
 		//