Mac doesn't need platform modifier for Go/Up key b=360735 r=CTho,ss

suite/browser/mac/platformNavigationBindings.xul

@@ -11,7 +11,6 @@
     <key keycode="&goForwardCmd.keyCode;" command="Browser:Forward" modifiers="accel"/>
     <key id="goBackKb" key="&goBackCmd.commandKey;" command="Browser:Back" modifiers="accel"/>
     <key id="goForwardKb" key="&goForwardCmd.commandKey;" command="Browser:Forward" modifiers="accel"/>
-    <key id="goUpKb" keycode="VK_UP" command="Browser:Up" modifiers="accel"/>
     <key id="key_stop2" keycode="VK_ESCAPE" oncommand="BrowserStop();"/>
     <key id="key_stop" key="." oncommand="BrowserStop();" modifiers="accel"/>
     <key id="goHome" keycode="VK_HOME" command="Browser:Home" modifiers="meta"/>

suite/browser/navigatorOverlay.xul

@@ -121,6 +121,7 @@
     <!-- Misc -->
           <!-- the amazing fishcam dept. -->
     <key key="f" modifiers="control,alt" oncommand="loadURI('http://home.netscape.com/fishcam/fishcam.html');"/>
+    <key id="goUpKb" keycode="VK_UP" modifiers="alt" command="Browser:Up"/>
     <key id="key_gotoHistory"  key="&history.commandKey;"        oncommand="toHistory();" modifiers="accel"/>
     <keyset id="viewZoomKeys"/>
     <keyset id="navigationKeys"/>  

suite/browser/unix/platformNavigationBindings.xul

@@ -9,7 +9,6 @@
     <!-- proper arrow key navigation, 4.xP -->
     <key id="goBackKb" keycode="&goBackCmd.keyCode;" command="Browser:Back" modifiers="alt"/>
     <key id="goForwardKb" keycode="&goForwardCmd.keyCode;" command="Browser:Forward" modifiers="alt"/>
-    <key id="goUpKb" keycode="VK_UP" command="Browser:Up" modifiers="alt"/>
 
     <!-- Some people apparently use this combination too on Unix...
          we live and learn.  -->

suite/browser/win/platformNavigationBindings.xul

@@ -10,7 +10,6 @@
          Alt+Left arrow and Alt+Right arrow. -->
     <key id="goBackKb"  keycode="&goBackCmd.keyCode;" command="Browser:Back" modifiers="alt"/>
     <key id="goForwardKb"  keycode="&goForwardCmd.keyCode;" command="Browser:Forward" modifiers="alt"/>
-    <key id="goUpKb"  keycode="VK_UP" command="Browser:Up" modifiers="alt"/>
     <key id="key_stop" keycode="VK_ESCAPE" oncommand="BrowserStop();"/>
 
     <!-- Supporting IE 'refresh' shortcut key -->