DevTools: appropriately hide the source map infobar

third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js

Index: third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js b/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
index 9bed9fd27036ef8170516abe7073cfa59e71a64a..63714a1c7208efc3cc79d7b9481c932d0fed3a68 100644
--- a/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
+++ b/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
@@ -1247,13 +1247,15 @@ Sources.JavaScriptSourceFrame = class extends SourceFrame.UISourceCodeFrame {
    * @param {boolean} show
    */
   _showSourceMapInfobar(show) {
-    if (this._sourceMapInfobar) {
-      if (!show) {
+    if (!show) {
+      if (this._sourceMapInfobar) {
         this._sourceMapInfobar.dispose();
         delete this._sourceMapInfobar;
       }
       return;
     }
+    if (this._sourceMapInfobar)
+      return;
     this._sourceMapInfobar = UI.Infobar.create(
         UI.Infobar.Type.Info, Common.UIString('Source Map detected.'),
         Common.settings.createSetting('sourceMapInfobarDisabled', false));