[Devtools] Canvas network timeline experiment establishes scrolling

third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js

Index: third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js b/third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js
index 00faa50fe523dd4191da8576dfea490f5f9d2ba0..a58fdda6660666f19c8bd082467a5ca12abbf7cf 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui_lazy/DataGrid.js
@@ -154,7 +154,8 @@ WebInspector.DataGrid.Events = {
     SelectedNode: Symbol("SelectedNode"),
     DeselectedNode: Symbol("DeselectedNode"),
     SortingChanged: Symbol("SortingChanged"),
-    ColumnsResized: Symbol("ColumnsResized")
+    ColumnsResized: Symbol("ColumnsResized"),
+    PaddingChanged: Symbol("PaddingChanged")

[dgozman, 2016/10/11 21:53:39]

HeightChanged or something like that? As a user of DataGrid, I don't know what
this means, especially since there is no direct method which affects this
padding.

Should we actually move this to ViewportDataGrid instead?

[allada, 2016/10/12 00:33:09]

There's a strange correlation between DataGrid and ViewportDataGrid. Some of the
code that viewport uses to manage it's viewport lives in datagrid and some of it
lives in it's own code. There are two clients of setVerticalPadding() one is
ViewportDataGrid the other is HeapSnapshotDataGrid.

I am fine renaming this, but I do not feel "HeightChanged" is appropriate
because the height is changing, but it can change without this being invoked.
"PaddingChanged" is what is happening and just happens to be all I need out of
it because it will never add padding if there is no need for a scrollbar.

 }
 
 /** @enum {string} */
@@ -297,6 +298,7 @@ WebInspector.DataGrid.prototype = {
             this._bottomFillerRow.style.height = bottom + "px";
         else
             this._bottomFillerRow.style.height = "auto";
+        this.dispatchEventToListeners(WebInspector.DataGrid.Events.PaddingChanged);
     },
 
     /**