Added showing slow scroll rectangles in Layers panel.

Source/devtools/front_end/layersPanel.css

Index: Source/devtools/front_end/layersPanel.css
diff --git a/Source/devtools/front_end/layersPanel.css b/Source/devtools/front_end/layersPanel.css
index c558fb809442529e34d0383bf33061bcd14d5895..7bb79e5d919632016a2cf5e57040a6f7ed65cd33 100644
--- a/Source/devtools/front_end/layersPanel.css
+++ b/Source/devtools/front_end/layersPanel.css
@@ -131,6 +131,11 @@
     border-style: solid;
 }
 
+.scroll-rect {
+    border: inherit solid rgb(178, 0, 0);

[caseq, 2014/02/20 16:30:45]

looks weird. should it be something like
border-width: inherit;
border: ...
?

[malch, 2014/02/21 12:22:15]

Done.

+    background-color: rgba(178, 0, 0, 0.2);
+}
+
 .layer-details-view .empty-view {
     font-size: 16px;
 }