MacViews: Handle Space and Return keys correctly for Buttons.

ui/views/style/platform_style.cc

Index: ui/views/style/platform_style.cc
diff --git a/ui/views/style/platform_style.cc b/ui/views/style/platform_style.cc
index 46ffecfaabc97983853eef28399047a61310d294..2f18ba6bedd3821b0e5119c8e858375e2a795be5 100644
--- a/ui/views/style/platform_style.cc
+++ b/ui/views/style/platform_style.cc
@@ -44,6 +44,9 @@ const bool PlatformStyle::kDialogDefaultButtonCanBeCancel = true;
 const bool PlatformStyle::kSelectWordOnRightClick = false;
 const CustomButton::NotifyAction PlatformStyle::kMenuNotifyActivationAction =
     CustomButton::NOTIFY_ON_RELEASE;
+const CustomButton::ButtonAction PlatformStyle::kButtonActionOnSpace =
+    CustomButton::ACTION_PRESS;
+const bool PlatformStyle::kClickControlOnReturn = true;
 const bool PlatformStyle::kTreeViewHasFocusRing = false;
 const bool PlatformStyle::kTreeViewSelectionPaintsEntireRow = false;
 const bool PlatformStyle::kUseRipples = true;