Speed up scrolling in downloads and extensions windows by (1) using background-color on elements with 'overflow: auto' and (2) not using 'background-attachment: fixed' unnecessarily. b=255812 r=kmgerich sr=ben

toolkit/themes/winstripe/mozapps/downloads/downloads.css

@@ -8,20 +8,14 @@
   margin: 10px 10px 5px 10px;
   -moz-appearance: listbox;
   -moz-user-focus: normal;
+  background-color: Window;
 }
 
-.downloadViewInner2 {
+.downloadViewInner {
   background-image: url("chrome://mozapps/skin/downloads/viewFader.png");
   padding: 0px;
 }  
 
-.downloadViewInner1 {
-  background-color: Window;
-  background-attachment: fixed;
-  background-repeat: no-repeat;
-  background-position: bottom right;
-}
-
 /* Download Manager Command Bar */
 #commandBar {
   padding: 0px 10px 5px 10px;

toolkit/themes/winstripe/mozapps/downloads/downloads.xml

@@ -1,19 +0,0 @@
-<?xml version="1.0"?>
-
-<bindings id="downloadSkinBindings"
-          xmlns="http://www.mozilla.org/xbl"
-          xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
-          xmlns:xbl="http://www.mozilla.org/xbl">
-
-  <binding id="download-view" extends="chrome://mozapps/content/downloads/download.xml#download-view">
-    <content>
-      <xul:vbox flex="1" class="downloadViewInner1">
-        <xul:vbox flex="1" class="downloadViewInner2">
-          <children/>
-        </xul:vbox>
-      </xul:vbox>
-    </content>
-  </binding>
- 
-</bindings>
-

toolkit/themes/winstripe/mozapps/shared/richview.css

@@ -4,18 +4,10 @@ view {
   margin: 10px 10px 5px 10px;
   -moz-appearance: listbox;
   -moz-user-focus: normal;
+  background-color: Window;
 }
 
-.richviewInner2 {
+.richviewInner {
   background-image: url("chrome://mozapps/skin/shared/viewFader.png");
   padding: 0px;
 }  
-
-.richviewInner1 {
-  background-color: Window;
-  background-image: inherit;
-  background-attachment: fixed;
-  background-repeat: no-repeat;
-  background-position: bottom right;
-}
-

toolkit/themes/winstripe/mozapps/shared/richview.xml

@@ -10,10 +10,8 @@
       <stylesheet src="chrome://mozapps/skin/shared/richview.css"/>
     </resources>
     <content>
-      <xul:vbox flex="1" class="richviewInner1">
-        <xul:vbox flex="1" class="richviewInner2">
-          <children/>
-        </xul:vbox>
+      <xul:vbox flex="1" class="richviewInner">
+        <children/>
       </xul:vbox>
     </content>
   </binding>