Replace pinch scrollbars with regular scrollbars.

Source/core/frame/VisualViewport.cpp

 /*
  * 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 255 matching lines @@
 //
 // *rootTransformLayer
 //  +- *innerViewportContainerLayer (fixed pos container)
 //  |   +- *overscrollElasticityLayer
 //  |       +- *pageScaleLayer
 //  |           +- *innerViewportScrollLayer
 //  |               +-- overflowControlsHostLayer (root layer)
 //  |                   +-- outerViewportContainerLayer (fixed pos container) [frame container layer in DeprecatedPaintLayerCompositor]
 //  |                   |   +-- outerViewportScrollLayer [frame scroll layer in DeprecatedPaintLayerCompositor]
 //  |                   |       +-- content layers ...
-//  |                   +-- horizontal ScrollbarLayer (non-overlay)
-//  |                   +-- verticalScrollbarLayer (non-overlay)
-//  |                   +-- scroll corner (non-overlay)
-//  +- *horizontalScrollbarLayer (overlay)
-//  +- *verticalScrollbarLayer (overlay)
+//  +- horizontalScrollbarLayer
+//  +- verticalScrollbarLayer
+//  +- scroll corner (non-overlay only)
 //
 void VisualViewport::attachToLayerTree(GraphicsLayer* currentLayerTreeRoot, GraphicsLayerFactory* graphicsLayerFactory)
 {
     TRACE_EVENT1("blink", "VisualViewport::attachToLayerTree", "currentLayerTreeRoot", (bool)currentLayerTreeRoot);
     if (!currentLayerTreeRoot) {
         if (m_innerViewportScrollLayer)
             m_innerViewportScrollLayer->removeAllChildren();
         return;
     }
 
@@ skipping 26 matching lines @@
         m_innerViewportContainerLayer->setSize(m_size);
 
         m_innerViewportScrollLayer->platformLayer()->setScrollClipLayer(
             m_innerViewportContainerLayer->platformLayer());
         m_innerViewportScrollLayer->platformLayer()->setUserScrollable(true, true);
 
         m_rootTransformLayer->addChild(m_innerViewportContainerLayer.get());
         m_innerViewportContainerLayer->addChild(m_overscrollElasticityLayer.get());
         m_overscrollElasticityLayer->addChild(m_pageScaleLayer.get());
         m_pageScaleLayer->addChild(m_innerViewportScrollLayer.get());
-        m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
-        m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
+
+        if (visualViewportSuppliesScrollbars()) {
+            m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
+            m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
+        }
 
         // Ensure this class is set as the scroll layer's ScrollableArea.
         coordinator->scrollableAreaScrollLayerDidChange(this);
 
         // Setup the inner viewport overlay scrollbars.
         setupScrollbar(WebScrollbar::Horizontal);
         setupScrollbar(WebScrollbar::Vertical);
     }
 
     m_innerViewportScrollLayer->removeAllChildren();
@@ skipping 24 matching lines @@
         ScrollingCoordinator* coordinator = frameHost().page().scrollingCoordinator();
         ASSERT(coordinator);
         ScrollbarOrientation webcoreOrientation = isHorizontal ? HorizontalScrollbar : VerticalScrollbar;
         webScrollbarLayer = coordinator->createSolidColorScrollbarLayer(webcoreOrientation, thumbThickness, scrollbarMargin, false);
 
         webScrollbarLayer->setClipLayer(m_innerViewportContainerLayer->platformLayer());
 
         // The compositor will control the scrollbar's visibility. Set to invisible by defualt
         // so scrollbars don't show up in layout tests.
         webScrollbarLayer->layer()->setOpacity(0);
-
         scrollbarGraphicsLayer->setContentsToPlatformLayer(webScrollbarLayer->layer());
         scrollbarGraphicsLayer->setDrawsContent(false);
     }
 
     int xPosition = isHorizontal ? 0 : m_innerViewportContainerLayer->size().width() - scrollbarThickness;
     int yPosition = isHorizontal ? m_innerViewportContainerLayer->size().height() - scrollbarThickness : 0;
     int width = isHorizontal ? m_innerViewportContainerLayer->size().width() - scrollbarThickness : scrollbarThickness;
     int height = isHorizontal ? scrollbarThickness : m_innerViewportContainerLayer->size().height() - scrollbarThickness;
 
     // Use the GraphicsLayer to position the scrollbars.
@@ skipping 18 matching lines @@
 
     m_webOverlayScrollbarHorizontal->setScrollLayer(scrollLayer);
     m_webOverlayScrollbarVertical->setScrollLayer(scrollLayer);
 
     ASSERT(compositor);
     layerTreeView->registerViewportLayers(
         m_overscrollElasticityLayer->platformLayer(),
         m_pageScaleLayer->platformLayer(),
         m_innerViewportScrollLayer->platformLayer(),
         scrollLayer);
+
+    // TODO(aelias): Remove this call after this setting is deleted.
+    layerTreeView->setHidePinchScrollbarsNearMinScale(false);
+}
+
+bool VisualViewport::visualViewportSuppliesScrollbars() const
+{
+    return frameHost().settings().viewportMetaEnabled();
 }
 
 void VisualViewport::clearLayersForTreeView(WebLayerTreeView* layerTreeView) const
 {
     ASSERT(layerTreeView);
 
     layerTreeView->clearViewportLayers();
 }
 
 DoubleRect VisualViewport::visibleContentRectDouble(IncludeScrollbarsInRect) const
@@ skipping 236 matching lines @@
     } else if (graphicsLayer == m_rootTransformLayer) {
         name =  "Root Transform Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink