Refactor RenderWidgetHost::set_paint_observer()

chrome/browser/renderer_host/render_widget_host.h

Index: chrome/browser/renderer_host/render_widget_host.h
diff --git a/chrome/browser/renderer_host/render_widget_host.h b/chrome/browser/renderer_host/render_widget_host.h
index 73d7fa4c265d8ead43de4c84bdcd5c6654d61d3f..2b30ee1483c1293d76c36b6aa7f05b2f627cd22e 100644
--- a/chrome/browser/renderer_host/render_widget_host.h
+++ b/chrome/browser/renderer_host/render_widget_host.h
@@ -42,7 +42,6 @@ class BackingStore;
 class PaintObserver;
 class RenderProcessHost;
 class RenderWidgetHostView;
-class RenderWidgetHostPaintingObserver;
 class TransportDIB;
 class WebCursor;
 struct ViewHostMsg_UpdateRect_Params;
@@ -124,14 +123,6 @@ struct ViewHostMsg_UpdateRect_Params;
 class RenderWidgetHost : public IPC::Channel::Listener,
                          public IPC::Channel::Sender {
  public:
-  // An interface that gets called before and after a paint.
-  class PaintObserver {
-   public:
-    virtual ~PaintObserver() {}
-    virtual void RenderWidgetHostWillPaint(RenderWidgetHost* rhw) = 0;
-    virtual void RenderWidgetHostDidPaint(RenderWidgetHost* rwh) = 0;
-  };
-
   // routing_id can be MSG_ROUTING_NONE, in which case the next available
   // routing id is taken from the RenderProcessHost.
   RenderWidgetHost(RenderProcessHost* process, int routing_id);
@@ -148,27 +139,12 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   int routing_id() const { return routing_id_; }
   bool renderer_accessible() { return renderer_accessible_; }
 
-  // Set the PaintObserver on this object. Takes ownership.
-  void set_paint_observer(PaintObserver* paint_observer) {
-    paint_observer_.reset(paint_observer);
-  }
-
   // Returns the property bag for this widget, where callers can add extra data
   // they may wish to associate with it. Returns a pointer rather than a
   // reference since the PropertyAccessors expect this.
   const PropertyBag* property_bag() const { return &property_bag_; }
   PropertyBag* property_bag() { return &property_bag_; }
 
-  // The painting observer that will be called for paint events. This
-  // pointer's ownership will remain with the caller and must remain valid
-  // until this class is destroyed or the observer is replaced.
-  RenderWidgetHostPaintingObserver* painting_observer() const {
-    return painting_observer_;
-  }
-  void set_painting_observer(RenderWidgetHostPaintingObserver* observer) {
-    painting_observer_ = observer;
-  }
-
   // Called when a renderer object already been created for this host, and we
   // just need to be attached to it. Used for window.open, <select> dropdown
   // menus, and other times when the renderer initiates creating an object.
@@ -219,10 +195,10 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   // web widget to match the |page_size| and then returns the bitmap
   // scaled so it matches the |desired_size|, so that the scaling
   // happens on the rendering thread.  When the bitmap is ready, the
-  // renderer sends a PaintAtSizeACK to this host, and the painting
-  // observer is notified.  Note that this bypasses most of the update
-  // logic that is normally invoked, and doesn't put the results into
-  // the backing store.
+  // renderer sends a PaintAtSizeACK to this host, and a
+  // RENDER_WIDGET_HOST_DID_RECEIVE_PAINT_AT_SIZE_ACK notification is issued.
+  // Note that this bypasses most of the update logic that is normally invoked,
+  // and doesn't put the results into the backing store.
   void PaintAtSize(TransportDIB::Handle dib_handle,
                    int tag,
                    const gfx::Size& page_size,
@@ -408,6 +384,15 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   // Activate deferred plugin handles.
   void ActivateDeferredPluginHandles();
 
+  // Used as the details object for a
+  // RENDER_WIDGET_HOST_DID_RECEIVE_PAINT_AT_SIZE_ACK notification.
+  struct PaintAtSizeAckDetails {

[brettw, 2011/01/10 19:18:47]

Since this is a type, it should go at the top of the public section above the
constructor (where the PaintObserver was before).

+    // The tag that was passed to the PaintAtSize() call that triggered this
+    // ack.
+    int tag;
+    gfx::Size size;
+  };
+
  protected:
   // Internal implementation of the public Forward*Event() methods.
   void ForwardInputEvent(const WebKit::WebInputEvent& input_event,
@@ -554,10 +539,6 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   // Stores random bits of data for others to associate with this object.
   PropertyBag property_bag_;
 
-  // Observer that will be called for paint events. This may be NULL. The
-  // pointer is not owned by this class.
-  RenderWidgetHostPaintingObserver* painting_observer_;
-
   // The ID of the corresponding object in the Renderer Instance.
   int routing_id_;
 
@@ -637,9 +618,6 @@ class RenderWidgetHost : public IPC::Channel::Listener,
   // This timer runs to check if time_when_considered_hung_ has past.
   base::OneShotTimer<RenderWidgetHost> hung_renderer_timer_;
 
-  // Optional observer that listens for notifications of painting.
-  scoped_ptr<PaintObserver> paint_observer_;
-
   // Flag to detect recursive calls to GetBackingStore().
   bool in_get_backing_store_;