Bug 567186 - When possible, set viewport size before page finishes loading [r=mfinkle]

mobile/chrome/content/browser-ui.js

@@ -158,6 +158,22 @@ var BrowserUI = {
     }
   },
 
+  _metaAdded : function(aEvent) {
+    let meta = aEvent.originalTarget;
+    if (!meta)
+      return;
+
+    if (meta.name == "viewport" || meta.name == "HandheldFriendly") {
+      // Must have an owner document and not be in a frame
+      var ownerDoc = meta.ownerDocument;
+      if (!ownerDoc || ownerDoc.defaultView.frameElement)
+        return;
+
+      let tab = Browser.getTabForDocument(ownerDoc);
+      tab.updateViewportMetadata();
+    }
+  },
+
   _linkAdded : function(aEvent) {
     let link = aEvent.originalTarget;
     if (!link || !link.href)
@@ -420,6 +436,7 @@ var BrowserUI = {
     // XXX these really want to listen to only the current browser
     browsers.addEventListener("DOMTitleChanged", this, true);
     browsers.addEventListener("DOMLinkAdded", this, true);
+    browsers.addEventListener("DOMMetaAdded", this, true);
     browsers.addEventListener("DOMWillOpenModalDialog", this, true);
 
     // listening mousedown for automatically dismiss some popups (e.g. larry)
@@ -728,6 +745,9 @@ var BrowserUI = {
       case "DOMLinkAdded":
         this._linkAdded(aEvent);
         break;
+      case "DOMMetaAdded":
+        this._metaAdded(aEvent);
+        break;
       case "DOMWindowClose":
         this._domWindowClose(aEvent);
         break;

mobile/chrome/content/browser.js

@@ -3081,10 +3081,10 @@ Tab.prototype = {
   /** Update browser size when the metadata or the window size changes. */
   updateViewportSize: function updateViewportSize() {
     let browser = this._browser;
-    let metaData = this._browserViewportState.metaData
-    if (!browser || !metaData)
+    if (!browser)
       return;
 
+    let metaData = this._browserViewportState.metaData || {};
     if (!metaData.autoSize) {
       let screenW = window.innerWidth;
       let screenH = window.innerHeight;
@@ -3144,12 +3144,17 @@ Tab.prototype = {
         Browser.scrollBrowserToContent();
       }
     }
+
+    this._browserViewportState.metaData = null;
+    this.updateViewportSize();
   },
 
   endLoading: function endLoading() {
     if (!this._loading) throw "Not Loading!";
 
-    this.updateViewportMetadata();
+    if (!this._browserViewportState.metaData)
+      this.updateViewportMetadata();
+
     this.setIcon(this._browser.mIconURL);
     this._loading = false;