Turn off favicon.ico and remove support for turning it on from the UI. r=hixie, sr=ben, a=asa

suite/browser/navigator.js

@@ -1554,12 +1554,13 @@ function SetPageProxyState(aState, aURI)
   if (aState == "valid") {
     gLastValidURLStr = gURLBar.value;
     gURLBar.addEventListener("input", UpdatePageProxyState, false);
-    if (pref.getBoolPref("browser.chrome.site_icons") && aURI && "schemeIs" in aURI && (aURI.schemeIs("http") || aURI.schemeIs("https"))) {
-      var favurl = gBrowser.buildFavIconString(aURI);
-      if (favurl != gProxyFavIcon.src) {
-        gProxyFavIcon.setAttribute("src", favurl);
+    if (gBrowser.shouldLoadFavIcon(aURI)) {
+      var favStr = gBrowser.buildFavIconString(aURI);
+      if (favStr != gProxyFavIcon.src) {
+        gBrowser.loadFavIcon(aURI, "src", gProxyFavIcon);
         gProxyDeck.selectedIndex = 0;
       }
+      else gProxyDeck.selectedIndex = 1;
     }
     else {
       gProxyDeck.selectedIndex = 0;

suite/browser/navigator.xul

@@ -184,7 +184,8 @@ Contributor(s): ______________________________________. -->
                        ondraggesture="PageProxyDragGesture(event);"/>
                 <image id="page-proxy-favicon" validate="never"
                        ondraggesture="PageProxyDragGesture(event);"
-                       onload="this.parentNode.selectedIndex = 1; event.stopPropagation(); event.preventBubble();"/>
+                       onload="this.parentNode.selectedIndex = 1; event.stopPropagation(); event.preventBubble();"
+                       onerror="gBrowser.addToMissedIconCache(this.src);"/>
               </deck>
               <menupopup id="ubhist-popup" class="autocomplete-history-popup"
                          popupalign="topleft" popupanchor="bottomleft"

suite/browser/nsBrowserStatusHandler.js

@@ -142,7 +142,7 @@ nsBrowserStatusHandler.prototype =
   },
 
   onLinkIconAvailable : function(aHref) {
-    if (gProxyFavIcon)
+    if (gProxyFavIcon && pref.getBoolPref("browser.chrome.site_icons"))
       gProxyFavIcon.setAttribute("src", aHref);
   },