[DevTools] Make async step in marker contiguous

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

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 497 matching lines @@
   }
 
   /**
    * @param {!MouseEvent} event
    */
   _onMouseMove(event) {
     if (this._executionLocation && this._controlDown && UI.KeyboardShortcut.eventHasCtrlOrMeta(event)) {
       if (!this._continueToLocationDecorations)
         this._showContinueToLocations();
     }
+    if (this._continueToLocationDecorations) {
+      this.textEditor.element.classList.toggle(
+          'source-frame-async-step-in-hovered',
+          !!event.target.enclosingNodeOrSelfWithClass('source-frame-async-step-in'));
+    }
   }
 
   /**
    * @param {!MouseEvent} event
    */
   _onMouseDown(event) {
     if (!this._executionLocation || !UI.KeyboardShortcut.eventHasCtrlOrMeta(event))
       return;
     if (!this._continueToLocationDecorations)
       return;
@@ skipping 380 matching lines @@
     });
   }
 
   _clearContinueToLocationsNoRestore() {
     if (!this._continueToLocationDecorations)
       return;
     this.textEditor.operation(() => {
       for (var decoration of this._continueToLocationDecorations.keys())
         this.textEditor.removeHighlight(decoration);
       this._continueToLocationDecorations = null;
+      this.textEditor.element.classList.remove('source-frame-async-step-in-hovered');
     });
   }
 
   _clearContinueToLocations() {
     if (!this._continueToLocationDecorations)
       return;
     this.textEditor.operation(() => {
       this.textEditor.showExecutionLineBackground();
       this._generateValuesInSource();
       this._clearContinueToLocationsNoRestore();
@@ skipping 643 matching lines @@
       return;
     this.bookmark.clear();
     this.bookmark = null;
   }
 };
 
 Sources.JavaScriptSourceFrame.BreakpointDecoration.bookmarkSymbol = Symbol('bookmark');
 Sources.JavaScriptSourceFrame.BreakpointDecoration._elementSymbolForTest = Symbol('element');
 
 Sources.JavaScriptSourceFrame.continueToLocationDecorationSymbol = Symbol('bookmark');