From 14605808e6932c3600a0b0166149019066c40654 Mon Sep 17 00:00:00 2001
From: Kartikaya Gupta <kgupta@mozilla.com>
Date: Fri, 15 Nov 2013 21:47:01 -0500
Subject: [PATCH] Bug 932792 - Don't apply APZC untransforms to mouse input on
 scrollbars. r=mbrubeck

---
 browser/metro/base/content/input.js | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/browser/metro/base/content/input.js b/browser/metro/base/content/input.js
index 7a74dc87502..0a7eff652f1 100644
--- a/browser/metro/base/content/input.js
+++ b/browser/metro/base/content/input.js
@@ -162,8 +162,17 @@ var TouchModule = {
             this._handleKeyDown(aEvent);
             break;
           case "MozMouseHittest":
-            // Used by widget to hit test chrome vs content
-            if (aEvent.target.ownerDocument == document) {
+            // Used by widget to hit test chrome vs content. Make sure the XUl scrollbars
+            // are counted as "chrome". Since the XUL scrollbars have sub-elements we walk
+            // the parent chain to ensure we catch all of those as well.
+            let onScrollbar = false;
+            for (let node = aEvent.originalTarget; node instanceof XULElement; node = node.parentNode) {
+              if (node.tagName == 'scrollbar') {
+                onScrollbar = true;
+                break;
+              }
+            }
+            if (onScrollbar || aEvent.target.ownerDocument == document) {
               aEvent.preventDefault();
             }
             aEvent.stopPropagation();