refactor for switch

context.go

@@ -743,16 +743,8 @@ func (c *Context) ClientIP() string {
 	switch c.engine.TrustedPlatform {
 	case "":
 		// TrustedPlatform is empty, do nothing
-	case PlatformGoogleAppEngine:
-		if addr := c.requestHeader("X-Appengine-Remote-Addr"); addr != "" {
-			return addr
-		}
-	case PlatformCloudflare:
-		if addr := c.requestHeader("CF-Connecting-IP"); addr != "" {
-			return addr
-		}
 	default:
-		// Developers can define their own header of Trusted Platform
+		// Developers can define their own header of Trusted Platform or use predefined constants
 		if addr := c.requestHeader(c.engine.TrustedPlatform); addr != "" {
 			return addr
 		}

gin.go

@@ -59,10 +59,10 @@ type RoutesInfo []RouteInfo
 const (
 	// When running on Google App Engine. Trust X-Appengine-Remote-Addr
 	// for determining the client's IP
-	PlatformGoogleAppEngine = "google-app-engine"
+	PlatformGoogleAppEngine = "X-Appengine-Remote-Addr"
 	// When using Cloudflare's CDN. Trust CF-Connecting-IP for determining
 	// the client's IP
-	PlatformCloudflare = "cloudflare"
+	PlatformCloudflare = "CF-Connecting-IP"
 )
 
 // Engine is the framework's instance, it contains the muxer, middleware and configuration settings.