DevTools: Initial implementation of line-level CPU profile.

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

Index: third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
diff --git a/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js b/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
index 8b6730246bfd24ec7e530708cf48f232c02e88e4..b26cadd1f6ecc6e011fe58895da2945d727fbcdd 100644
--- a/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
+++ b/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
@@ -39,6 +39,8 @@ WebInspector.CodeMirrorTextEditor = function(url, delegate)
     WebInspector.VBox.call(this);
     this._delegate = delegate;
     this._url = url;
+    /** @type {!Set<number>}} */
+    this._gutterMarkers = new Set();
 
     this.registerRequiredCSS("cm/codemirror.css");
     this.registerRequiredCSS("source_frame/cmdevtools.css");
@@ -1118,6 +1120,29 @@ WebInspector.CodeMirrorTextEditor.prototype = {
 
     /**
      * @param {number} lineNumber
+     * @param {string} type
+     * @param {?Element} element
+     */
+    setGutterMarker: function(lineNumber, type, element)
+    {
+        if (element) {
+            if (!this._gutterMarkers.size) {
+                this._codeMirror.setOption("gutters", ["CodeMirror-linenumbers", "CodeMirror-linemarkers-" + type]);
+                this._codeMirror.refresh();
+            }
+            this._gutterMarkers.add(lineNumber);
+        } else {
+            this._gutterMarkers.delete(lineNumber);
+            if (!this._gutterMarkers.size) {
+                this._codeMirror.setOption("gutters", ["CodeMirror-linenumbers"]);
+                this._codeMirror.refresh();
+            }
+        }
+        this._codeMirror.setGutterMarker(lineNumber, "CodeMirror-linemarkers-" + type, element);

[pfeldman, 2016/03/07 19:57:50]

Throttle using operation?

[alph, 2016/03/08 00:57:42]

It's already wrapped inside CM.

+    },
+
+    /**
+     * @param {number} lineNumber
      * @param {number} columnNumber
      */
     setExecutionLocation: function(lineNumber, columnNumber)