[Mac] Don't show tooltip when zoom decoration is hidden.

chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm

Index: chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
diff --git a/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm b/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
index 992baaeb3cd70d22d8c2218d850c2d6cd9ad396a..2bdc753e136e078db4e682a9ff4a1b9269a4f7e0 100644
--- a/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
+++ b/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
@@ -104,7 +104,9 @@ void ZoomDecoration::ShowAndUpdateUI(zoom::ZoomController* zoom_controller,
 
   SetImage(GetMaterialIcon(location_bar_is_dark));
 
-  tooltip_.reset([tooltip_string retain]);
+  tooltip_.reset(vector_icon_id_ == gfx::VectorIconId::VECTOR_ICON_NONE

[Avi (use Gerrit), 2016/10/12 19:40:10]

It's equivalent, but it feels better to do:

tooltip_.reset(relative_zoom == zoom::ZoomController::ZOOM_AT_DEFAULT_ZOOM
 ? @""
 : [tooltip_string retain]);

where we're gating on the zoom controller's response rather than an id
interpretation of it.

[shrike, 2016/10/12 20:43:36]

I like checking the icon id because it's explicit that no vector icon means no
tool tip either, but I'm fine to change it.

+                     ? @""
+                     : [tooltip_string retain]);
 
   SetVisible(true);
   [bubble_ onZoomChanged];