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

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

Index: third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js b/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
index ba21103a76c773253dd7910ba92e154fa5baa14d..855bac3c075023589a596be156264fd6e7a2fb68 100644
--- a/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
+++ b/third_party/WebKit/Source/devtools/front_end/console/ConsoleView.js
@@ -178,8 +178,6 @@ Console.ConsoleView = class extends UI.VBox {
     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()

   }
 
   /**
@@ -303,7 +301,7 @@ Console.ConsoleView = class extends UI.VBox {
    * @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.

   }
 
   /**