MacViews: Handle Space and Return keys correctly for Buttons.

ui/views/style/platform_style_mac.mm

 // Copyright 2015 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.
 
 #include "ui/views/style/platform_style.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_features.h"
 #include "ui/gfx/color_utils.h"
@@ skipping 19 matching lines @@
 
 // On Mac, the Cocoa browser window does not flip its UI in RTL (e.g. bookmark
 // star remains on the right, padlock on the left). So bubbles should open in
 // the same direction as in LTR by default, unless the entire browser is views.
 const bool PlatformStyle::kMirrorBubbleArrowInRTLByDefault =
     BUILDFLAG(MAC_VIEWS_BROWSER);
 
 const CustomButton::NotifyAction PlatformStyle::kMenuNotifyActivationAction =
     CustomButton::NOTIFY_ON_PRESS;
 
+const CustomButton::ButtonAction PlatformStyle::kButtonActionOnSpace =
+    CustomButton::ACTION_CLICK;
+
+// On Mac, the Return Key is used to perform the default action even when a
+// control is focused.
+const bool PlatformStyle::kClickControlOnReturn = false;
+
 // static
 gfx::ImageSkia PlatformStyle::CreateComboboxArrow(bool is_enabled,
                                                   Combobox::Style style) {
   // TODO(ellyjones): IDR_MENU_DROPARROW is a cross-platform image that doesn't
   // look right on Mac. See https://crbug.com/384071.
   if (style == Combobox::STYLE_ACTION) {
     ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
     return *rb.GetImageSkiaNamed(IDR_MENU_DROPARROW);
   }
   const int kComboboxArrowWidth = 24;
@@ skipping 28 matching lines @@
   ButtonColorByState& colors = *color_by_state;
   colors[Button::STATE_PRESSED] = SK_ColorWHITE;
 }
 
 // static
 void PlatformStyle::OnTextfieldEditFailed() {
   NSBeep();
 }
 
 }  // namespace views