Add VectorIconButton functionality to ImageButton.

chrome/browser/ui/views/chrome_views_delegate.cc

Index: chrome/browser/ui/views/chrome_views_delegate.cc
diff --git a/chrome/browser/ui/views/chrome_views_delegate.cc b/chrome/browser/ui/views/chrome_views_delegate.cc
index 20793d9fc5e0ff082b4013cfcd6fbb4a45a30e1a..c89b0ddbb9da7cb11c7925d4035cb2a90d320d2c 100644
--- a/chrome/browser/ui/views/chrome_views_delegate.cc
+++ b/chrome/browser/ui/views/chrome_views_delegate.cc
@@ -268,6 +268,11 @@ int ChromeViewsDelegate::GetDefaultDistanceMetric(
   return views::ViewsDelegate::GetDistanceMetric(metric);
 }
 
+gfx::Insets ChromeViewsDelegate::GetButtonMargins() const {
+  return gfx::Insets(
+      LayoutDelegate::Get()->GetMetric(LayoutDelegate::Metric::BUTTON_MARGIN));
+}
+
 #if !defined(OS_CHROMEOS)
 views::Widget::InitParams::WindowOpacity
 ChromeViewsDelegate::GetOpacityForInitParams(