Add autoscroll pref to advanced. For now, autoscroll is on by default on linux because we haven't forked the linux prefs override file, unix.js.

browser/app/profile/all.js

@@ -51,6 +51,7 @@ pref("general.useragent.vendor", "Mozilla Firebird");
 pref("general.useragent.vendorSub", "0.6.1+");
 
 pref("general.smoothScroll", false);
+pref("general.autoScroll", true);
 
 pref("backups.number_of_prefs_copies", 1);
 

browser/app/profile/firebird.js

@@ -51,6 +51,7 @@ pref("general.useragent.vendor", "Mozilla Firebird");
 pref("general.useragent.vendorSub", "0.6.1+");
 
 pref("general.smoothScroll", false);
+pref("general.autoScroll", true);
 
 pref("backups.number_of_prefs_copies", 1);
 

browser/components/prefwindow/content/pref-advanced.xul

@@ -12,9 +12,9 @@
   <script type="application/x-javascript">
     <![CDATA[
       var _elementIDs = ["moveSystemCaret", "hideTabBar",
-                         "loadInBackground", "useSmoothScrolling",
-                         "enableAutoImageResizing", "useSSL2",
-                         "useSSL3", "useTLS1"];
+                         "loadInBackground", "useAutoScrolling",
+                         "useSmoothScrolling", "enableAutoImageResizing",
+                         "useSSL2", "useSSL3", "useTLS1"];
     ]]>
   </script>
 
@@ -28,6 +28,8 @@
                 prefstring="browser.tabs.autoHide"/>
       <checkbox id="loadInBackground" label="&loadInBackground.label;"
                 prefstring="browser.tabs.loadInBackground"/>
+      <checkbox id="useAutoScrolling" label="&useAutoScrolling.label;" 
+                prefstring="general.autoScroll"/>
       <checkbox id="useSmoothScrolling" label="&useSmoothScrolling.label;"
                 prefstring="general.smoothScroll"/>
     </expander>

browser/components/prefwindow/locale/pref-advanced.dtd

@@ -7,6 +7,7 @@
 <!ENTITY browsing.label               "Browsing">
 <!ENTITY hideTabBar.label             "Hide the tab bar when only one website is open">
 <!ENTITY loadInBackground.label       "Open links in the background">
+<!ENTITY useAutoScrolling.label       "Use autoscrolling">
 <!ENTITY useSmoothScrolling.label     "Use smooth scrolling">
 <!ENTITY multimedia.label             "Multimedia">
 <!ENTITY enableAutoImageResizing.label "Enable Automatic Image Resizing">

toolkit/content/widgets/browser.xml

@@ -49,6 +49,24 @@
         </getter>
       </property>
 
+      <property name="autoscrollEnabled">
+        <getter>
+          <![CDATA[
+            if (this.getAttribute("autoscroll") == "false")
+              return false;
+            
+            var enabled = true;
+            try {
+              enabled = this.mPrefs.getBoolPref("general.autoScroll");
+            }
+            catch(ex) {
+            }
+            
+            return enabled;
+          ]]>
+        </getter>
+      </property>
+
       <property name="canGoBack"
                 onget="return this.webNavigation.canGoBack;"
                 readonly="true"/>
@@ -607,16 +625,17 @@
           }
         ]]>
       </handler>
-#ifdef XP_WIN
       <handler event="mouseup">
         <![CDATA[
+          if (!this.autoscrollEnabled)
+            return;
           if (!this._snapOn)
             this.stopScroll();
         ]]>        
       </handler>
       <handler event="mousedown">
         <![CDATA[
-          if (this.getAttribute("autoscroll") == "false" || this.isLink(event.originalTarget))
+          if (!this.autoscrollEnabled || this.isLink(event.originalTarget))
             return;
 
           if (!this._isScrolling) {
@@ -650,7 +669,6 @@
           }
         ]]>
       </handler>
-#endif
     </handlers>
 
   </binding>