views: add Harmony dialog width support

ui/views/window/dialog_delegate.cc

Index: ui/views/window/dialog_delegate.cc
diff --git a/ui/views/window/dialog_delegate.cc b/ui/views/window/dialog_delegate.cc
index d98274cde71a90871a5fd96875f70838ca61cb3f..c966d6a3b323e410ca96da14efe31c7a9494190d 100644
--- a/ui/views/window/dialog_delegate.cc
+++ b/ui/views/window/dialog_delegate.cc
@@ -10,6 +10,7 @@
 #include "build/build_config.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/material_design/material_design_controller.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/bubble/bubble_border.h"
@@ -224,6 +225,12 @@ DialogClientView* DialogDelegate::GetDialogClientView() {
   return GetWidget()->client_view()->AsDialogClientView();
 }
 
+int DialogDelegate::GetWidthFactor() const {
+  if (!ui::MaterialDesignController::IsSecondaryUiMaterial())
+    return 0;
+  return static_cast<int>(dialog_width_);
+}
+
 ui::AXRole DialogDelegate::GetAccessibleWindowRole() const {
   return ui::AX_ROLE_DIALOG;
 }