Fix double delete of ImageLoadingTracker in BrowserActionButton.

chrome/browser/gtk/browser_actions_toolbar_gtk.cc

Index: chrome/browser/gtk/browser_actions_toolbar_gtk.cc
diff --git a/chrome/browser/gtk/browser_actions_toolbar_gtk.cc b/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
index 176b4eec52fa112dd70bef890fe3d674cb615dd1..fb36c0db76a301bca42e8793e03f167988cec541 100644
--- a/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
+++ b/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
@@ -105,6 +105,7 @@ class BrowserActionButton : public NotificationObserver,
   void OnImageLoaded(SkBitmap* image, size_t index) {
     if (image)
       default_icon_ = gfx::GdkPixbufFromSkBitmap(image);
+    tracker_ = NULL;  // The tracker object will delete itself when we return.
     UpdateState();
   }