Added showing slow scroll rectangles in Layers panel.

Source/core/inspector/InspectorLayerTreeAgent.cpp

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 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.
@@ skipping 55 matching lines @@
     }
     int layerId;
     RefPtr<GraphicsContextSnapshot> graphicsSnapshot;
 };
 
 inline String idForLayer(const GraphicsLayer* graphicsLayer)
 {
     return String::number(graphicsLayer->platformLayer()->id());
 }
 
+static PassRefPtr<TypeBuilder::LayerTree::ScrollRect> buildScrollRect(const blink::WebRect& rect, const TypeBuilder::LayerTree::ScrollRect::Type::Enum& type)
+{
+    RefPtr<TypeBuilder::DOM::Rect> rectObject = TypeBuilder::DOM::Rect::create()
+        .setX(rect.x)
+        .setY(rect.y)
+        .setHeight(rect.height)
+        .setWidth(rect.width);
+    RefPtr<TypeBuilder::LayerTree::ScrollRect> scrollRectObject = TypeBuilder::LayerTree::ScrollRect::create()
+        .setRect(rectObject.release())
+        .setType(type);
+    return scrollRectObject.release();
+}
+
+static PassRefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > buildScrollRectsForLayer(GraphicsLayer* graphicsLayer)
+{
+    RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > scrollRects = TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect>::create();
+    blink::WebLayer* webLayer = graphicsLayer->platformLayer();
+    for (size_t i = 0; i < webLayer->nonFastScrollableRegion().size(); ++i) {
+        scrollRects->addItem(buildScrollRect(webLayer->nonFastScrollableRegion()[i], TypeBuilder::LayerTree::ScrollRect::Type::RepaintsOnScroll));
+    }
+    for (size_t i = 0; i < webLayer->touchEventHandlerRegion().size(); ++i) {
+        scrollRects->addItem(buildScrollRect(webLayer->touchEventHandlerRegion()[i], TypeBuilder::LayerTree::ScrollRect::Type::TouchEventHandler));
+    }
+    if (webLayer->haveWheelEventHandlers()) {
+        blink::WebRect* webRect = new blink::WebRect(webLayer->position().x, webLayer->position().y, webLayer->bounds().width, webLayer->bounds().height);

[caseq, 2014/03/11 12:04:09]

that's a memory leak. Why do you need a dynamic allocation here?

[malch, 2014/03/11 12:48:49]

Done.

+        scrollRects->addItem(buildScrollRect(*webRect, TypeBuilder::LayerTree::ScrollRect::Type::WheelEventHandler));
+    }
+    return scrollRects->length() ? scrollRects.release() : nullptr;
+}
+
 static PassRefPtr<TypeBuilder::LayerTree::Layer> buildObjectForLayer(GraphicsLayer* graphicsLayer, int nodeId)
 {
     blink::WebLayer* webLayer = graphicsLayer->platformLayer();
     RefPtr<TypeBuilder::LayerTree::Layer> layerObject = TypeBuilder::LayerTree::Layer::create()
         .setLayerId(idForLayer(graphicsLayer))
         .setOffsetX(webLayer->position().x)
         .setOffsetY(webLayer->position().y)
         .setWidth(webLayer->bounds().width)
         .setHeight(webLayer->bounds().height)
         .setPaintCount(graphicsLayer->paintCount());
@@ skipping 14 matching lines @@
         transform.toColumnMajorFloatArray(flattenedMatrix);
         RefPtr<TypeBuilder::Array<double> > transformArray = TypeBuilder::Array<double>::create();
         for (size_t i = 0; i < WTF_ARRAY_LENGTH(flattenedMatrix); ++i)
             transformArray->addItem(flattenedMatrix[i]);
         layerObject->setTransform(transformArray);
         const FloatPoint3D& anchor = graphicsLayer->anchorPoint();
         layerObject->setAnchorX(anchor.x());
         layerObject->setAnchorY(anchor.y());
         layerObject->setAnchorZ(anchor.z());
     }
+    RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::ScrollRect> > scrollRects =
+        buildScrollRectsForLayer(graphicsLayer);

[caseq, 2014/03/11 12:04:09]

nit: please don't wrap here, it's well within reasonable line length.

[malch, 2014/03/11 12:48:49]

Done.

+    if (scrollRects)
+        layerObject->setScrollRects(scrollRects.release());
     return layerObject;
 }
 
 InspectorLayerTreeAgent::InspectorLayerTreeAgent(InspectorDOMAgent* domAgent, Page* page)
     : InspectorBaseAgent<InspectorLayerTreeAgent>("LayerTree")
     , m_frontend(0)
     , m_page(page)
     , m_domAgent(domAgent)
 {
 }
@@ skipping 233 matching lines @@
 void InspectorLayerTreeAgent::didRemovePageOverlay(const GraphicsLayer* layer)
 {
     size_t index = m_pageOverlayLayerIds.find(layer->platformLayer()->id());
     if (index == WTF::kNotFound)
         return;
     m_pageOverlayLayerIds.remove(index);
 }
 
 
 } // namespace WebCore