Draggable region support for frameless app window on Windows.

content/browser/renderer_host/render_view_host_delegate.h

Index: content/browser/renderer_host/render_view_host_delegate.h
diff --git a/content/browser/renderer_host/render_view_host_delegate.h b/content/browser/renderer_host/render_view_host_delegate.h
index bfbac694a33c2af399ee5f670bc87b0bfa843729..40add38d40371e9c521d3f3b69fc486217211d30 100644
--- a/content/browser/renderer_host/render_view_host_delegate.h
+++ b/content/browser/renderer_host/render_view_host_delegate.h
@@ -56,6 +56,7 @@ class SessionStorageNamespace;
 class WebContents;
 struct ContextMenuParams;
 struct FileChooserParams;
+struct DraggableRegion;
 struct GlobalRequestID;
 struct NativeWebKeyboardEvent;
 struct Referrer;
@@ -405,6 +406,10 @@ class CONTENT_EXPORT RenderViewHostDelegate {
       const MediaStreamRequest* request,
       const MediaResponseCallback& callback) {}
 
+  // The draggable regions should be updated if they're supported.
+  virtual void UpdateDraggableRegions(
+      const std::vector<content::DraggableRegion>& regions) {}
+
  protected:
   virtual ~RenderViewHostDelegate() {}
 };