[DevTools] Rendering option description cleanup

third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js

Index: third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js
diff --git a/third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js b/third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js
index c24678bacc62f17230da158e36b18e14e0f86699..8d7f4114cf32b2e4dbbafbb532a296c4d4a596ad 100644
--- a/third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js
+++ b/third_party/WebKit/Source/devtools/front_end/main/RenderingOptions.js
@@ -42,7 +42,7 @@ Main.RenderingOptionsView = class extends UI.VBox {
     var options = [
       {
         label: Common.UIString('Paint Flashing'),
-        subtitle: Common.UIString('Highlights areas of the page that need to be repainted'),
+        subtitle: Common.UIString('Highlights areas of the page (green) that need to be repainted'),
         setterName: 'setShowPaintRects'
       },
       {
@@ -57,10 +57,8 @@ Main.RenderingOptionsView = class extends UI.VBox {
       },
       {
         label: Common.UIString('Scrolling Performance Issues'),
-        subtitle: Common.UIString('Shows areas of the page that slow down scrolling'),
-        setterName: 'setShowScrollBottleneckRects',
-        tooltip:
-            'Touch and mousewheel event listeners can delay scrolling.\nSome areas need to repaint their content when scrolled.'
+        subtitle: Common.UIString('Highlights elements (teal) that can slow down scrolling, including touch & wheel event handlers and other main-thread scrolling situations.'),
+        setterName: 'setShowScrollBottleneckRects'
       }
     ];
     for (var i = 0; i < options.length; i++)