Bug 1096013 - [e10s] Improve perceived session restore duration by prioritizing selected tabs when restoring session history and by setting tab labels and icons as soon as possible to indicate a restored session r=smacleod

browser/components/sessionstore/SessionStore.jsm

@@ -635,21 +635,8 @@ let SessionStoreInternal = {
           let uri = activePageData ? activePageData.url || null : null;
           browser.userTypedValue = uri;
 
-          // If the page has a title, set it.
-          if (activePageData) {
-            if (activePageData.title) {
-              tab.label = activePageData.title;
-              tab.crop = "end";
-            } else if (activePageData.url != "about:blank") {
-              tab.label = activePageData.url;
-              tab.crop = "center";
-            }
-          }
-
-          // Restore the tab icon.
-          if ("image" in tabData) {
-            win.gBrowser.setIcon(tab, tabData.image);
-          }
+          // Update tab label and icon again after the tab history was updated.
+          this.updateTabLabelAndIcon(tab, tabData);
 
           let event = win.document.createEvent("Events");
           event.initEvent("SSTabRestoring", true, false);
@@ -1860,6 +1847,26 @@ let SessionStoreInternal = {
     }
   },
 
+  updateTabLabelAndIcon(tab, tabData) {
+    let activePageData = tabData.entries[tabData.index - 1] || null;
+
+    // If the page has a title, set it.
+    if (activePageData) {
+      if (activePageData.title) {
+        tab.label = activePageData.title;
+        tab.crop = "end";
+      } else if (activePageData.url != "about:blank") {
+        tab.label = activePageData.url;
+        tab.crop = "center";
+      }
+    }
+
+    // Restore the tab icon.
+    if ("image" in tabData) {
+      tab.ownerDocument.defaultView.gBrowser.setIcon(tab, tabData.image);
+    }
+  },
+
   /**
    * Restores the session state stored in LastSession. This will attempt
    * to merge data into the current session. If a window was opened at startup
@@ -2532,9 +2539,17 @@ let SessionStoreInternal = {
       this._windows[aWindow.__SSi].selected = aSelectTab;
     }
 
+    // If we restore the selected tab, make sure it goes first.
+    let selectedIndex = aTabs.indexOf(tabbrowser.selectedTab);
+    if (selectedIndex > -1) {
+      this.restoreTab(tabbrowser.selectedTab, aTabData[selectedIndex]);
+    }
+
     // Restore all tabs.
     for (let t = 0; t < aTabs.length; t++) {
-      this.restoreTab(aTabs[t], aTabData[t]);
+      if (t != selectedIndex) {
+        this.restoreTab(aTabs[t], aTabData[t]);
+      }
     }
   },
 
@@ -2640,6 +2655,10 @@ let SessionStoreInternal = {
     browser.messageManager.sendAsyncMessage("SessionStore:restoreHistory",
                                             {tabData: tabData, epoch: epoch});
 
+    // Update tab label and icon to show something
+    // while we wait for the messages to be processed.
+    this.updateTabLabelAndIcon(tab, tabData);
+
     // Restore tab attributes.
     if ("attributes" in tabData) {
       TabAttributes.set(tab, tabData.attributes);