Remove surface_id from RenderWidget/RenderWidgetHost and friends

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 11b99ee5d42f249434d4694dc0d146e014263cf9..a58e626d6f6193123bb922236e92de27ef7dc7a8 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -95,7 +95,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   RenderWidgetHostImpl(RenderWidgetHostDelegate* delegate,
                        RenderProcessHost* process,
                        int32_t routing_id,
-                       int32_t surface_id,
                        bool hidden);
   ~RenderWidgetHostImpl() override;
 
@@ -172,8 +171,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl
 
   RenderWidgetHostDelegate* delegate() const { return delegate_; }
 
-  int surface_id() const { return surface_id_; }
-
   bool empty() const { return current_size_.IsEmpty(); }
 
   // Called when a renderer object already been created for this host, and we
@@ -698,9 +695,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // The ID of the corresponding object in the Renderer Instance.
   const int routing_id_;
 
-  // The ID of the surface corresponding to this render widget.
-  int surface_id_;
-
   // Indicates whether a page is loading or not.
   bool is_loading_;