DevTools: make console viewport less error prone by always defining cumulativeHeights

third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 160 matching lines @@
 
     ConsoleModel.consoleModel.addEventListener(
         ConsoleModel.ConsoleModel.Events.ConsoleCleared, this._consoleCleared, this);
     ConsoleModel.consoleModel.addEventListener(
         ConsoleModel.ConsoleModel.Events.MessageAdded, this._onConsoleMessageAdded, this);
     ConsoleModel.consoleModel.addEventListener(
         ConsoleModel.ConsoleModel.Events.MessageUpdated, this._onConsoleMessageUpdated, this);
     ConsoleModel.consoleModel.addEventListener(
         ConsoleModel.ConsoleModel.Events.CommandEvaluated, this._commandEvaluated, this);
     ConsoleModel.consoleModel.messages().forEach(this._addConsoleMessage, this);
-    if (this._consoleMessages.length)
-      this._viewport.invalidate();

[luoe, 2017/04/07 01:19:38]

drive by: Orthogonal to the root problem, but we don't need to invalidate until
the console wasShown()

   }
 
   /**
    * @return {!Console.ConsoleView}
    */
   static instance() {
     if (!Console.ConsoleView._instance)
       Console.ConsoleView._instance = new Console.ConsoleView();
     return Console.ConsoleView._instance;
   }
@@ skipping 103 matching lines @@
    * @override
    */
   willHide() {
     this._hidePromptSuggestBox();
   }
 
   /**
    * @override
    */
   wasShown() {
-    this._viewport.refresh();
+    this._viewport.invalidate();

[dgozman, 2017/04/07 20:31:44]

Why this change?

[luoe, 2017/04/07 22:09:54]

I actually think we don't need this at all!  Maybe we can get rid of it?  It was
introduced in the original viewport impl so perhaps lushnikov@ knows.

   }
 
   /**
    * @override
    */
   focus() {
     if (this._prompt.hasFocus())
       return;
     // Set caret position before setting focus in order to avoid scrolling
     // by focus().
@@ skipping 968 matching lines @@
         return true;
     }
     return false;
   }
 };
 
 /**
  * @typedef {{messageIndex: number, matchIndex: number}}
  */
 Console.ConsoleView.RegexMatchRange;