Minor changes to chromedp-gen/build.sh

cmd/chromedp-gen/.gitignore

@@ -0,0 +1 @@
+.last

cmd/chromedp-gen/build.sh

@@ -1,10 +1,26 @@
 #!/bin/bash
 
-set -ve
+UPDATE=0
+LASTUPDATE=0
+if [ -f .last ]; then
+  LASTUPDATE=$(cat .last)
+fi
+
+NOW=$(date +%s)
+if (( "$NOW" >= $(($LASTUPDATE + 86400*5)) )); then
+  UPDATE=1
+fi
+
+if [[ "$UPDATE" == 1 ]]; then
   go get -u \
+    golang.org/x/tools/cmd/goimports \
     github.com/mailru/easyjson/easyjson \
     github.com/valyala/quicktemplate/qtc
 
+  date +%s > .last
+fi
+
+set -ve
 go generate
 
 gofmt -w -s templates/*.go

cmd/chromedp-gen/internal/domain.go

@@ -19,6 +19,7 @@ const (
 	DomainConsole           DomainType = "Console"
 	DomainDOM               DomainType = "DOM"
 	DomainDOMDebugger       DomainType = "DOMDebugger"
+	DomainDOMSnapshot       DomainType = "DOMSnapshot"
 	DomainDOMStorage        DomainType = "DOMStorage"
 	DomainDatabase          DomainType = "Database"
 	DomainDebugger          DomainType = "Debugger"
@@ -83,6 +84,8 @@ func (dt *DomainType) UnmarshalJSON(buf []byte) error {
 		*dt = DomainDOM
 	case DomainDOMDebugger:
 		*dt = DomainDOMDebugger
+	case DomainDOMSnapshot:
+		*dt = DomainDOMSnapshot
 	case DomainDOMStorage:
 		*dt = DomainDOMStorage
 	case DomainDatabase: