Draggable region support for frameless app window on Windows.

content/public/browser/web_contents_delegate.h

Index: content/public/browser/web_contents_delegate.h
diff --git a/content/public/browser/web_contents_delegate.h b/content/public/browser/web_contents_delegate.h
index e9bc5614cfa9197ef414bcf092bc5c41a74002d2..dd7dd8f6cd99cd1d2306d560f529d511e2fe6ae8 100644
--- a/content/public/browser/web_contents_delegate.h
+++ b/content/public/browser/web_contents_delegate.h
@@ -37,6 +37,7 @@ class RenderViewHost;
 class WebContents;
 class WebIntentsDispatcher;
 struct ContextMenuParams;
+struct DraggableRegion;
 struct FileChooserParams;
 struct NativeWebKeyboardEvent;
 struct SSLStatus;
@@ -418,6 +419,10 @@ class CONTENT_EXPORT WebContentsDelegate {
       const MediaStreamRequest* request,
       const MediaResponseCallback& callback) {}
 
+  // Invoked when the draggable regions have been changed.
+  virtual void UpdateDraggableRegions(
+    const std::vector<content::DraggableRegion>& regions) {};
+
  protected:
   virtual ~WebContentsDelegate();