AppMenu: add accessibility descriptions to zoom buttons

chrome/browser/ui/cocoa/app_menu/app_menu_controller.mm

 // Copyright (c) 2011 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/app_menu/app_menu_controller.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/mac/bundle_locations.h"
@@ skipping 343 matching lines @@
 
   zoom_level_observer_.reset(
       new AppMenuControllerInternal::ZoomLevelObserver(
           self,
           ui_zoom::ZoomEventManager::GetForBrowserContext(
               browser_->profile())));
   NSString* title = base::SysUTF16ToNSString(
       [self appMenuModel]->GetLabelForCommandId(IDC_ZOOM_PERCENT_DISPLAY));
   [[[buttonViewController_ zoomItem] viewWithTag:IDC_ZOOM_PERCENT_DISPLAY]
       setTitle:title];
+  [[[[buttonViewController_ zoomItem]
+      viewWithTag:IDC_ZOOM_MINUS] image]
+          setAccessibilityDescription:l10n_util::GetNSString(
+              IDS_TEXT_SMALLER_MAC)];
+  [[[[buttonViewController_ zoomItem]
+      viewWithTag:IDC_ZOOM_PLUS] image]
+        setAccessibilityDescription:l10n_util::GetNSString(
+              IDS_TEXT_BIGGER_MAC)];
   content::RecordAction(UserMetricsAction("ShowAppMenu"));
 
   NSImage* icon = [self appMenuModel]->browser()->window()->IsFullscreen()
                       ? [NSImage imageNamed:NSImageNameExitFullScreenTemplate]
                       : [NSImage imageNamed:NSImageNameEnterFullScreenTemplate];
   [[buttonViewController_ zoomFullScreen] setImage:icon];
 
   menuOpenTime_ = base::TimeTicks::Now();
 }
 
@@ skipping 252 matching lines @@
   // (and thus, after all our ability to adjust it normally). Throw in the
   // towel, and simply don't let the frame move from where it's supposed to be.
   // TODO(devlin): Yet another Cocoa hack. It'd be good to find a workaround,
   // but unlikely unless we replace the Cocoa menu implementation.
   NSView* containerSuperview = [overflowActionsContainerView_ superview];
   if (NSMinX([containerSuperview frame]) != 0)
     [containerSuperview setFrameOrigin:NSZeroPoint];
 }
 
 @end  // @implementation AppMenuButtonViewController