Reduce FOR_EACH_OBSERVER usage in content/browser/renderer_host

content/browser/renderer_host/render_widget_host_view_base.cc

Index: content/browser/renderer_host/render_widget_host_view_base.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_base.cc b/content/browser/renderer_host/render_widget_host_view_base.cc
index a0e03e50e2b4c1e66af709659cfc08a86e26b0ac..955f0f97d111d46a7c6fc1f3b7a7219159bbf673 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.cc
+++ b/content/browser/renderer_host/render_widget_host_view_base.cc
@@ -80,9 +80,8 @@ RenderWidgetHost* RenderWidgetHostViewBase::GetRenderWidgetHost() const {
 void RenderWidgetHostViewBase::NotifyObserversAboutShutdown() {
   // Note: RenderWidgetHostInputEventRouter is an observer, and uses the
   // following notification to remove this view from its surface owners map.
-  FOR_EACH_OBSERVER(RenderWidgetHostViewBaseObserver,
-                    observers_,
-                    OnRenderWidgetHostViewBaseDestroyed(this));
+  for (auto& observer : observers_)
+    observer.OnRenderWidgetHostViewBaseDestroyed(this);
   // All observers are required to disconnect after they are notified.
   DCHECK(!observers_.might_have_observers());
 }