Remove GraphicsLayer::didScroll and directly call ScrollableArea::didScroll

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 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 1134 matching lines @@
 }
 
 void GraphicsLayer::setScrollableArea(ScrollableArea* scrollableArea,
                                       bool isVisualViewport) {
   if (m_scrollableArea == scrollableArea)
     return;
 
   m_scrollableArea = scrollableArea;
 
   // VisualViewport scrolling may involve pinch zoom and gets routed through
-  // WebViewImpl explicitly rather than via GraphicsLayer::didScroll since it
+  // WebViewImpl explicitly rather than via ScrollableArea::didScroll since it
   // needs to be set in tandem with the page scale delta.
   if (isVisualViewport)
-    m_layer->layer()->setScrollClient(0);
+    m_layer->layer()->setScrollClient(nullptr);
   else
-    m_layer->layer()->setScrollClient(this);
-}
-
-void GraphicsLayer::didScroll() {
-  if (m_scrollableArea) {
-    ScrollOffset newOffset =
-        toFloatSize(m_layer->layer()->scrollPositionDouble() -
-                    m_scrollableArea->scrollOrigin());
-    m_scrollableArea->setScrollOffset(newOffset, CompositorScroll);
-  }
+    m_layer->layer()->setScrollClient(scrollableArea);
 }
 
 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 GraphicsLayer::TakeDebugInfo(cc::Layer* layer) {
   std::unique_ptr<base::trace_event::TracedValue> tracedValue(
       m_debugInfo.asTracedValue());
   tracedValue->SetString(
       "layer_name", WTF::StringUTF8Adaptor(debugName(layer)).asStringPiece());
   return std::move(tracedValue);
 }
@@ skipping 150 matching lines @@
 void showGraphicsLayerTree(const blink::GraphicsLayer* layer) {
   if (!layer) {
     LOG(INFO) << "Cannot showGraphicsLayerTree for (nil).";
     return;
   }
 
   String output = layer->layerTreeAsText(blink::LayerTreeIncludesDebugInfo);
   LOG(INFO) << output.utf8().data();
 }
 #endif