Hide the browser actions gripper when it's not in use.

chrome/browser/gtk/browser_actions_toolbar_gtk.h

Index: chrome/browser/gtk/browser_actions_toolbar_gtk.h
diff --git a/chrome/browser/gtk/browser_actions_toolbar_gtk.h b/chrome/browser/gtk/browser_actions_toolbar_gtk.h
index 467d9ea4fb4b050615b703f4e8f57cdc88200c1f..e26b55585f9c06e53f0a03cf129a4c72facfca2f 100644
--- a/chrome/browser/gtk/browser_actions_toolbar_gtk.h
+++ b/chrome/browser/gtk/browser_actions_toolbar_gtk.h
@@ -195,6 +195,10 @@ class BrowserActionsToolbarGtk : public ExtensionToolbarModel::Observer,
   // This is the width we were at when we started animating.
   int start_width_;
 
+  // We only draw the browser action gripper when the user is hovering over it
+  // or dragging it.
+  bool draw_gripper_;
+
   GtkSignalRegistrar signals_;
 
   ScopedRunnableMethodFactory<BrowserActionsToolbarGtk> method_factory_;