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

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/location_bar/zoom_decoration.h"
 
 #include "base/i18n/number_formatting.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
@@ skipping 24 matching lines @@
   if (!ShouldShowDecoration()) {
     if (!IsVisible() && !bubble_)
       return false;
 
     HideUI();
     return true;
   }
 
   base::string16 zoom_percent =
       base::FormatPercent(zoom_controller->GetZoomPercent());
-  NSString* zoom_string =
-      l10n_util::GetNSStringF(IDS_TOOLTIP_ZOOM, zoom_percent);
+  // In Material Design there is no icon at the default zoom factor (100%), so
+  // don't display a tooltip either.
+  NSString* tooltip_string =
+      zoom_controller->IsAtDefaultZoom()
+          ? @""
+          : l10n_util::GetNSStringF(IDS_TOOLTIP_ZOOM, zoom_percent);
 
-  if (IsVisible() && [tooltip_ isEqualToString:zoom_string] &&
+  if (IsVisible() && [tooltip_ isEqualToString:tooltip_string] &&
       !default_zoom_changed) {
     return false;
   }
 
-  ShowAndUpdateUI(zoom_controller, zoom_string, location_bar_is_dark);
+  ShowAndUpdateUI(zoom_controller, tooltip_string, location_bar_is_dark);
   return true;
 }
 
 void ZoomDecoration::ShowBubble(BOOL auto_close) {
   if (bubble_) {
     bubble_.delegate = nil;
     [[bubble_.window parentWindow] removeChildWindow:bubble_.window];
     [bubble_.window orderOut:nil];
     [bubble_ closeWithoutAnimation];
   }
@@ skipping 25 matching lines @@
   [bubble_ close];
   SetVisible(false);
 }
 
 void ZoomDecoration::ShowAndUpdateUI(zoom::ZoomController* zoom_controller,
                                      NSString* tooltip_string,
                                      bool location_bar_is_dark) {
   vector_icon_id_ = gfx::VectorIconId::VECTOR_ICON_NONE;
   zoom::ZoomController::RelativeZoom relative_zoom =
       zoom_controller->GetZoomRelativeToDefault();
+  // In Material Design there is no icon at the default zoom factor.
   if (relative_zoom == zoom::ZoomController::ZOOM_BELOW_DEFAULT_ZOOM) {
     vector_icon_id_ = gfx::VectorIconId::ZOOM_MINUS;
   } else if (relative_zoom == zoom::ZoomController::ZOOM_ABOVE_DEFAULT_ZOOM) {
     vector_icon_id_ = gfx::VectorIconId::ZOOM_PLUS;
   }
 
   SetImage(GetMaterialIcon(location_bar_is_dark));
 
   tooltip_.reset([tooltip_string retain]);
 
@@ skipping 50 matching lines @@
   // closed the decoration can be hidden.
   if (IsAtDefaultZoom() && IsVisible()) {
     SetVisible(false);
     owner_->OnDecorationsChanged();
   }
 }
 
 gfx::VectorIconId ZoomDecoration::GetMaterialVectorIconId() const {
   return vector_icon_id_;
 }