CC Animation: Use ElementId to attach CC animation players.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 537 matching lines @@
     if (layoutObject->isLayoutPart()) {
         if (PaintLayerCompositor::attachFrameContentLayersToIframeLayer(toLayoutPart(layoutObject)))
             layerConfigChanged = true;
     }
 
     // Changes to either the internal hierarchy or the mask layer have an impact
     // on painting phases, so we need to update when either are updated.
     if (layerConfigChanged || maskLayerChanged)
         updatePaintingPhases();
 
-    updateElementIdAndCompositorMutableProperties();
+    updateCompositorElementId();
+    updateCompositorMutableProperties();
 
     return layerConfigChanged;
 }
 
 static IntRect clipBox(LayoutBox* layoutObject)
 {
     LayoutRect result = LayoutRect(LayoutRect::infiniteIntRect());
     if (layoutObject->hasOverflowClip() || layoutObject->style()->containsPaint())
         result = layoutObject->overflowClipRect(LayoutPoint());
 
@@ skipping 165 matching lines @@
     updateChildClippingMaskLayerGeometry();
 
     if (m_owningLayer.getScrollableArea() && m_owningLayer.getScrollableArea()->scrollsOverflow())
         m_owningLayer.getScrollableArea()->positionOverflowControls();
 
     updateLayerBlendMode(layoutObject()->styleRef());
     updateIsRootForIsolatedGroup();
     updateContentsRect();
     updateBackgroundColor();
     updateDrawsContent();
-    updateElementIdAndCompositorMutableProperties();
+    updateCompositorElementId();
+    updateCompositorMutableProperties();
     updateContentsOpaque();
     updateAfterPartResize();
     updateRenderingContext();
     updateShouldFlattenTransform();
     updateChildrenTransform();
     updateScrollParent(scrollParent());
     registerScrollingLayers();
 
     updateCompositingReasons();
 }
@@ skipping 726 matching lines @@
     // Regardless, mark the graphics layer, scrolling layer and scrolling block
     // selection layer (if they exist) as not flattening. Having them flatten
     // causes unclipped render surfaces which cause bugs.
     // http://crbug.com/521768
     if (hasScrollingLayer()) {
         m_graphicsLayer->setShouldFlattenTransform(false);
         m_scrollingLayer->setShouldFlattenTransform(false);
     }
 }
 
-void CompositedLayerMapping::updateElementIdAndCompositorMutableProperties()
+void CompositedLayerMapping::updateCompositorElementId()
+{
+    if (Node* owningNode = m_owningLayer.layoutObject()->generatingNode()) {

[esprehn, 2016/05/10 22:55:13]

we can just keep a data member on CompositedLayerMapping for this, CLM must
exist if anything in cc exists, and if CLM is destroyed anything in cc must be
destroyed too.

If the question is about CompositorWorker then we should use DOMNodeIds.

[loyso (OOO), 2016/05/12 06:02:15]

Do you mean
Node* CompositedLayerMapping::m_owningNode 
or
CompositorElementId CompositedLayerMapping::m_compositorElementId (a unique for
CompositedLayerMapping, 1 per CLM)
?

+        if (owningNode->isElementNode()) {
+            Element* owningElement = toElement(owningNode);
+            if (owningElement->layoutObject() == m_owningLayer.layoutObject()) {
+                CompositorElementId elementId = owningElement->compositorElementId();
+                if (m_scrollingContentsLayer.get()) {
+                    // Any scrolling layer may attract compositor-initiated
+                    // animation, so assign an id in advance.
+                    elementId = owningElement->assignCompositorElementId();
+                    m_scrollingContentsLayer->setElementId(elementId);
+                }
+                m_graphicsLayer->setElementId(elementId);
+            }
+        }
+    }
+}
+
+void CompositedLayerMapping::updateCompositorMutableProperties()
 {
     if (!RuntimeEnabledFeatures::compositorWorkerEnabled())
         return;
 
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("compositor-worker"), "CompositedLayerMapping::updateElementId()");
 
-    CompositorElementId elementId = 0;
     uint32_t mainMutableProperties = CompositorMutableProperty::kNone;
     uint32_t scrollMutableProperties = CompositorMutableProperty::kNone;
 
     if (m_owningLayer.layoutObject()->style()->hasCompositorProxy()) {
         if (Node* owningNode = m_owningLayer.layoutObject()->generatingNode()) {
             if (owningNode->isElementNode()) {
                 Element* owningElement = toElement(owningNode);
+
+                const CompositorElementId elementId = owningElement->assignCompositorElementId();
+                CompositorIdToElementMap::registerElement(*owningElement);
+                m_graphicsLayer->setElementId(elementId);
+                if (m_scrollingContentsLayer.get())
+                    m_scrollingContentsLayer->setElementId(elementId);
+
                 uint32_t compositorMutableProperties = owningElement->compositorMutableProperties();
-                elementId = owningElement->assignCompositorElementId();
-                CompositorIdToElementMap::registerElement(*owningElement);
                 mainMutableProperties = (CompositorMutableProperty::kOpacity | CompositorMutableProperty::kTransform) & compositorMutableProperties;
                 scrollMutableProperties = (CompositorMutableProperty::kScrollLeft | CompositorMutableProperty::kScrollTop) & compositorMutableProperties;
             }
         }
     }
 
-    m_graphicsLayer->setElementId(elementId);
     m_graphicsLayer->setCompositorMutableProperties(mainMutableProperties);
-
-    if (m_scrollingContentsLayer.get()) {
-        m_scrollingContentsLayer->setElementId(elementId);
+    if (m_scrollingContentsLayer.get())
         m_scrollingContentsLayer->setCompositorMutableProperties(scrollMutableProperties);
-    }
 }
 
 bool CompositedLayerMapping::updateForegroundLayer(bool needsForegroundLayer)
 {
     bool layerChanged = false;
     if (needsForegroundLayer) {
         if (!m_foregroundLayer) {
             m_foregroundLayer = createGraphicsLayer(CompositingReasonLayerForForeground);
             layerChanged = true;
         }
@@ skipping 1042 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink