Unbreak tabs.onRemove extension API in face of fast tab closure

chrome/browser/ui/unload_controller.cc

Index: chrome/browser/ui/unload_controller.cc
diff --git a/chrome/browser/ui/unload_controller.cc b/chrome/browser/ui/unload_controller.cc
index 19d61540a760ae4b3e23d49db68ebd3de73ce377..010b2877b9dd6be228ac7b75ec8ab001347cd15e 100644
--- a/chrome/browser/ui/unload_controller.cc
+++ b/chrome/browser/ui/unload_controller.cc
@@ -162,7 +162,8 @@ void UnloadController::TabInsertedAt(content::WebContents* contents,
 }
 
 void UnloadController::TabDetachedAt(content::WebContents* contents,
-                                     int index) {
+                                     int index,
+                                     bool closing_all) {
   TabDetachedImpl(contents);
 }
 
@@ -221,9 +222,10 @@ bool UnloadController::DetachWebContents(content::WebContents* contents) {
   if (index != TabStripModel::kNoTab &&
       contents->NeedToFireBeforeUnload()) {
     tabs_needing_unload_ack_.insert(contents);
+    CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(contents);
+    core_tab_helper->OnUnloadAboutToDetach();
     browser_->tab_strip_model()->DetachWebContentsAt(index);
     contents->SetDelegate(detached_delegate_.get());
-    CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(contents);
     core_tab_helper->OnUnloadDetachedStarted();
     return true;
   }