cc: Create a LayerScrollClient interface and an adapter class in compositor_bindings.

webkit/renderer/compositor_bindings/web_layer_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/renderer/compositor_bindings/web_layer_impl.h"
 
 #include "base/strings/string_util.h"
 #include "cc/animation/animation.h"
 #include "cc/base/region.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "third_party/WebKit/public/platform/WebCompositingReasons.h"
 #include "third_party/WebKit/public/platform/WebFloatPoint.h"
 #include "third_party/WebKit/public/platform/WebFloatRect.h"
 #include "third_party/WebKit/public/platform/WebLayerPositionConstraint.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/skia/include/utils/SkMatrix44.h"
 #include "webkit/renderer/compositor_bindings/web_animation_impl.h"
 #include "webkit/renderer/compositor_bindings/web_filter_operations_impl.h"
 #include "webkit/renderer/compositor_bindings/web_to_cc_animation_delegate_adapter.h"
+#include "webkit/renderer/compositor_bindings/web_to_cc_layer_scroll_client_adapter.h"
 
 using cc::Animation;
 using cc::Layer;
 using WebKit::WebLayer;
 using WebKit::WebFloatPoint;
 using WebKit::WebVector;
 using WebKit::WebRect;
 using WebKit::WebSize;
 using WebKit::WebColor;
 using WebKit::WebFilterOperations;
@@ skipping 320 matching lines @@
     const WebKit::WebLayerPositionConstraint& constraint) {
   layer_->SetPositionConstraint(ToLayerPositionConstraint(constraint));
 }
 
 WebKit::WebLayerPositionConstraint WebLayerImpl::positionConstraint() const {
   return ToWebLayerPositionConstraint(layer_->position_constraint());
 }
 
 void WebLayerImpl::setScrollClient(
     WebKit::WebLayerScrollClient* scroll_client) {
-  layer_->set_layer_scroll_client(scroll_client);
+  layer_scroll_client_adapter_.reset(
+      new WebToCCLayerScrollClientAdapter(scroll_client));
+  layer_->set_layer_scroll_client(layer_scroll_client_adapter_.get());

[danakj, 2013/06/28 02:57:48]

To do this with base::Callback, you'd add a method here

static void PassAlongDidScroll(WebLayerScrollClient* scroll_client) {
  scroll_client->didScroll();
}

Then you'd give to cc something like

layer->set_did_scroll_callback(base::Bind(&PassAlongDidScroll,
base::Unretained(scroll_client)));

Then cc receives and stores a base::Closure that it calls Run() on instead of
calling client->DidScroll().

[danakj, 2013/06/28 02:59:02]

Actually, you shouldn't need the PassAlong method. You should be able to just
give cc a base::Bind(WebLayerScrollClient::didScroll,
base::Unretained(scroll_client)) I believe.

[tfarina, 2013/06/28 04:07:03]

Done.

 }
 
 bool WebLayerImpl::isOrphan() const { return !layer_->layer_tree_host(); }
 
 Layer* WebLayerImpl::layer() const { return layer_.get(); }
 
 }  // namespace webkit