(NOT FOR COMMIT) Testing layer invalidation speedups.

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

Index: third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
index e9ff85796c123d3768c11ef81048390a6f1f42b8..eaa7c4c506ab677383ce2cae403b6f0de2d5067f 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
@@ -2052,33 +2052,41 @@ void CompositedLayerMapping::setContentsNeedDisplay()
     ApplyToGraphicsLayers(this, SetContentsNeedsDisplayFunctor(), ApplyToContentLayers);
 }
 
-struct SetContentsNeedsDisplayInRectFunctor {
-    void operator() (GraphicsLayer* layer) const
-    {
-        if (layer->drawsContent()) {
-            IntRect layerDirtyRect = r;
-            layerDirtyRect.move(-layer->offsetFromLayoutObject());
-            layer->setNeedsDisplayInRect(layerDirtyRect, invalidationReason, client);
-        }
-    }
-
-    IntRect r;
-    PaintInvalidationReason invalidationReason;
-    const DisplayItemClient& client;
-};
-
 // r is in the coordinate space of the layer's layout object
 void CompositedLayerMapping::setContentsNeedDisplayInRect(const LayoutRect& r, PaintInvalidationReason invalidationReason, const DisplayItemClient& client)
 {
     // TODO(wangxianzhu): Enable the following assert after paint invalidation for spv2 is ready.
     // ASSERT(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
 
-    SetContentsNeedsDisplayInRectFunctor functor = {
+    NeedsDisplayRecord record {
         enclosingIntRect(LayoutRect(r.location() + m_owningLayer.subpixelAccumulation(), r.size())),
         invalidationReason,
         client
     };
-    ApplyToGraphicsLayers(this, functor, ApplyToContentLayers);
+
+    m_needsDisplayInRects.append(record);
+}
+
+struct SetContentsNeedsDisplayInRectsFunctor {
+    void operator()(GraphicsLayer* layer) const
+    {
+        if (layer->drawsContent()) {
+            layer->setNeedsDisplayInRect(needsDisplayInRects);
+        }
+    }
+
+    const Vector<NeedsDisplayRecord>& needsDisplayInRects;
+};
+
+void CompositedLayerMapping::finalizeInvalidations()
+{
+    if (m_needsDisplayInRects.size()) {
+        SetContentsNeedsDisplayInRectsFunctor functor = {
+            m_needsDisplayInRects
+        };
+        ApplyToGraphicsLayers(this, functor, ApplyToContentLayers);
+        m_needsDisplayInRects.clear();
+    }
 }
 
 void CompositedLayerMapping::invalidateDisplayItemClient(const DisplayItemClient& displayItemClient, PaintInvalidationReason paintInvalidationReason)