Views/Harmony: Use LayoutDelegate::GetMetric() for views::kPanelHorizMargin.

chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc

Index: chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc
diff --git a/chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc b/chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc
index 4a7487d786bbb09ea63d1a93294ce66ac97f8f70..19ad08d2fd1a7cbf24481e02cdb273b31fa890df 100644
--- a/chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc
+++ b/chrome/browser/ui/views/extensions/media_galleries_dialog_views.cc
@@ -9,6 +9,7 @@
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/views/extensions/media_gallery_checkbox_view.h"
+#include "chrome/browser/ui/views/harmony/layout_delegate.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/grit/locale_settings.h"
 #include "components/constrained_window/constrained_window_views.h"
@@ -145,7 +146,9 @@ void MediaGalleriesDialogViews::InitChildViews() {
       header->SetMultiLine(true);
       header->SetHorizontalAlignment(gfx::ALIGN_LEFT);
       header->SetBorder(views::CreateEmptyBorder(
-          views::kRelatedControlVerticalSpacing, views::kPanelHorizMargin,
+          views::kRelatedControlVerticalSpacing,
+          LayoutDelegate::Get()->GetMetric(
+              LayoutDelegate::Metric::PANEL_CONTENT_MARGIN),
           views::kRelatedControlVerticalSpacing, 0));
       scroll_container->AddChildView(header);
     }