Organize Layout/Paint-related hooks (blink-side).

public/web/WebWidgetClient.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 60 matching lines @@
 
     // Return a compositing view used for this widget. This is owned by the
     // WebWidgetClient.
     virtual WebLayerTreeView* layerTreeView() { return 0; }
     // FIXME: Remove all overrides of this and change layerTreeView() above to ASSERT_NOT_REACHED.
     virtual bool allowsBrokenNullLayerTreeView() const { return false; }
 
     // Called when a call to WebWidget::animate is required
     virtual void scheduleAnimation() { }
 
+    // Called when one of the following things were involved during the layout:
+    // * > 200 text characters
+    // * > 1024 image pixels
+    // * a plugin
+    // * a canvas
+    // An approximation for first layout that resulted in pixels on screen.
+    // Not the best heuristic, and we should replace it with something better.
+    virtual void didFirstVisuallyNonEmptyLayout() { }
+
+    // The frame's document first layout immediately after the parsing finished.
+    // Another way to put it: first frame produced after DOMContentLoaded was dispatched.
+    virtual void didFirstLayoutAfterFinishedParsing() { }
+
     // Called when the widget acquires or loses focus, respectively.
     virtual void didFocus() { }
     virtual void didBlur() { }
 
     // Called when the cursor for the widget changes.
     virtual void didChangeCursor(const WebCursorInfo&) { }
 
     // Called when the widget should be closed.  WebWidget::close() should
     // be called asynchronously as a result of this notification.
     virtual void closeWidgetSoon() { }
@@ skipping 80 matching lines @@
     // press or gesture tap.
     // Note: This is called even when the mouse down event is prevent default.
     virtual void onMouseDown(const WebNode& mouseDownNode) { }
 protected:
     ~WebWidgetClient() { }
 };
 
 } // namespace blink
 
 #endif