Disable LabelButtonTest.ButtonStyleIsDefaultStyle on Mac

This fails on 10.10 only because the system bold font doesn't change its
width enough to cause the test expecations to fail. But we don't care
about styled LabelButtons on Mac -- just MdTextButton, so just disable
on Mac.

TBR=ellyjones@chromium.org

Bug: 779937
Change-Id: I941c6b0ce9ee7bd6e4794519c7a6129e0dace7d5
Reviewed-on: https://chromium-review.googlesource.com/746064Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512763}

ui/views/controls/button/label_button_unittest.cc

@@ -8,6 +8,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/material_design/material_design_controller.h"
@@ -384,7 +385,14 @@ TEST_F(LabelButtonTest, ChangeLabelImageSpacing) {
 
 // Ensure the label gets the correct style for default buttons (e.g. bolding)
 // and button size updates correctly. Regression test for crbug.com/578722.
-TEST_F(LabelButtonTest, ButtonStyleIsDefaultStyle) {
+// Disabled on Mac. The system bold font on 10.10 doesn't get wide enough to
+// change the size, but we don't use styled buttons on Mac, just MdTextButton.
+#if defined(OS_MACOSX)
+#define MAYBE_ButtonStyleIsDefaultStyle DISABLED_ButtonStyleIsDefaultStyle
+#else
+#define MAYBE_ButtonStyleIsDefaultStyle ButtonStyleIsDefaultStyle
+#endif
+TEST_F(LabelButtonTest, MAYBE_ButtonStyleIsDefaultStyle) {
   TestLabelButton* button = AddStyledButton("Save", false);
   gfx::Size non_default_size = button->label()->size();
   EXPECT_EQ(button->label()->GetPreferredSize().width(),