browser part of 47909 - hide the progress meter when it's not needed

r=neil sr=bz

xpfe/browser/resources/content/navigator.xul

@@ -328,7 +328,7 @@ Contributor(s):
              ondragdrop="nsDragAndDrop.drop(event, contentAreaDNDObserver);">
     <statusbarpanel id="component-bar"/>
     <statusbarpanel id="statusbar-display" label="&statusText.label;" flex="1"/>
-    <statusbarpanel class="statusbarpanel-progress">
+    <statusbarpanel class="statusbarpanel-progress" id="progress-panel" hidden="true">
       <progressmeter class="progressmeter-statusbar" id="statusbar-icon" mode="normal" value="0"/>
     </statusbarpanel>
     <statusbarpanel id="popupIcon" class="statusbarpanel-iconic" hidden="true" oncommand="StatusbarViewPopupManager()" tooltiptext="&popupIcon.tooltiptext;"/>

xpfe/browser/resources/content/nsBrowserStatusHandler.js

@@ -66,6 +66,7 @@ nsBrowserStatusHandler.prototype =
     this.urlBar          = document.getElementById("urlbar");
     this.throbberElement = document.getElementById("navigator-throbber");
     this.statusMeter     = document.getElementById("statusbar-icon");
+    this.statusPanel     = document.getElementById("progress-panel");
     this.stopButton      = document.getElementById("stop-button");
     this.stopMenu        = document.getElementById("menuitem-stop");
     this.stopContext     = document.getElementById("context-stop");
@@ -84,6 +85,7 @@ nsBrowserStatusHandler.prototype =
     this.urlBar          = null;
     this.throbberElement = null;
     this.statusMeter     = null;
+    this.statusPanel     = null;
     this.stopButton      = null;
     this.stopMenu        = null;
     this.stopContext     = null;
@@ -184,6 +186,8 @@ nsBrowserStatusHandler.prototype =
           aRequest && aWebProgress.DOMWindow == content)
         this.startDocumentLoad(aRequest);
 
+      // Show the progress meter
+      this.statusPanel.removeAttribute("hidden");
       // Turn the throbber on.
       this.throbberElement.setAttribute("busy", "true");
 
@@ -243,6 +247,7 @@ nsBrowserStatusHandler.prototype =
       }
 
       // Turn the progress meter and throbber off.
+      this.statusPanel.setAttribute("hidden", "true");
       this.statusMeter.value = 0;  // be sure to clear the progress bar
       this.throbberElement.removeAttribute("busy");