DevTools: Don't refresh CodeMirror if it is hidden

third_party/WebKit/Source/devtools/front_end/source_frame/SourcesTextEditor.js

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @extends {WebInspector.CodeMirrorTextEditor}
  * @param {!WebInspector.SourcesTextEditorDelegate} delegate
  */
 WebInspector.SourcesTextEditor = function(delegate)
@@ skipping 156 matching lines @@
     {
         if (this._gutters.indexOf(type) !== -1)
             return;
 
         if (leftToNumbers)
             this._gutters.unshift(type);
         else
             this._gutters.push(type);
 
         this.codeMirror().setOption("gutters", this._gutters.slice());
-        this.codeMirror().refresh();
+        this.refresh();
     },
 
     /**
      * @param {string} type
      */
     uninstallGutter: function(type)
     {
+        var originalLength = this._gutters.length;

[lushnikov, 2016/09/14 19:02:35]

indexOf..

         this._gutters = this._gutters.filter(gutter => gutter !== type);
+        if (originalLength === this._gutters.length)
+            return;
         this.codeMirror().setOption("gutters", this._gutters.slice());
-        this.codeMirror().refresh();
+        this.refresh();
     },
 
     /**
      * @param {number} lineNumber
      * @param {string} type
      * @param {?Element} element
      */
     setGutterDecoration: function(lineNumber, type, element)
     {
         console.assert(this._gutters.indexOf(type) !== -1, "Cannot decorate unexisting gutter.")
@@ skipping 787 matching lines @@
         this._codeMirror.addOverlay(overlayMode);
         this._highlightDescriptor = {
             overlay: overlayMode,
             selectionStart: selectionStart
         };
     }
 }
 
 WebInspector.SourcesTextEditor.LinesToScanForIndentationGuessing = 1000;
 WebInspector.SourcesTextEditor.MaximumNumberOfWhitespacesPerSingleSpan = 16;