From bac99222f312a672d854fdf4b3f5ddc0c7211048 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 19 Sep 2014 15:09:43 -0600
Subject: [PATCH] Force scrollbars to be GPU layers when acceleration is
 enabled
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Fixes #3559

For some reason, Chromium 37 is not compositing scrollbars correctly on
secondary monitors in OS X. They’re invisible when the lines layer
extends beneath the scrollbars unless we apply this style.
---
 src/editor-component.coffee    | 2 ++
 src/scrollbar-component.coffee | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/src/editor-component.coffee b/src/editor-component.coffee
index fb9d7216e..90de158d5 100644
--- a/src/editor-component.coffee
+++ b/src/editor-component.coffee
@@ -128,6 +128,7 @@ EditorComponent = React.createClass
           scrollableInOppositeDirection: verticallyScrollable
           verticalScrollbarWidth: verticalScrollbarWidth
           horizontalScrollbarHeight: horizontalScrollbarHeight
+          useHardwareAcceleration: @useHardwareAcceleration
 
       ScrollbarComponent
         ref: 'verticalScrollbar'
@@ -140,6 +141,7 @@ EditorComponent = React.createClass
         scrollableInOppositeDirection: horizontallyScrollable
         verticalScrollbarWidth: verticalScrollbarWidth
         horizontalScrollbarHeight: horizontalScrollbarHeight
+        useHardwareAcceleration: @useHardwareAcceleration
 
       # Also used to measure the height/width of scrollbars after the initial render
       ScrollbarCornerComponent
diff --git a/src/scrollbar-component.coffee b/src/scrollbar-component.coffee
index 4a494da5e..1e23d686c 100644
--- a/src/scrollbar-component.coffee
+++ b/src/scrollbar-component.coffee
@@ -9,9 +9,11 @@ ScrollbarComponent = React.createClass
   render: ->
     {orientation, className, scrollHeight, scrollWidth, visible} = @props
     {scrollableInOppositeDirection, horizontalScrollbarHeight, verticalScrollbarWidth} = @props
+    {useHardwareAcceleration} = @props
 
     style = {}
     style.display = 'none' unless visible
+    style.transform = 'translateZ(0)' if useHardwareAcceleration # See atom/atom#3559
     switch orientation
       when 'vertical'
         style.width = verticalScrollbarWidth