Reland of place 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 31 matching lines @@
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "platform/TraceEvent.h"
 #include "platform/geometry/DoubleRect.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/graphics/GraphicsLayerFactory.h"
 #include "platform/scroll/Scrollbar.h"
-#include "platform/scroll/ScrollbarTheme.h"
+#include "platform/scroll/ScrollbarThemeOverlay.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCompositorSupport.h"
 #include "public/platform/WebLayer.h"
 #include "public/platform/WebLayerTreeView.h"
 #include "public/platform/WebScrollbar.h"
 #include "public/platform/WebScrollbarLayer.h"
 
 using blink::WebLayer;
 using blink::WebLayerTreeView;
 using blink::WebScrollbar;
@@ skipping 36 matching lines @@
         && mainFrame()->settings()
         && mainFrame()->settings()->textAutosizingEnabled();
 
     TRACE_EVENT2("blink", "VisualViewport::setSize", "width", size.width(), "height", size.height());
     m_size = size;
 
     if (m_innerViewportContainerLayer) {
         m_innerViewportContainerLayer->setSize(m_size);
 
         // Need to re-compute sizes for the overlay scrollbars.
-        setupScrollbar(WebScrollbar::Horizontal);
-        setupScrollbar(WebScrollbar::Vertical);
+        initializeScrollbars();
     }
 
     if (autosizerNeedsUpdating) {
         // This needs to happen after setting the m_size member since it'll be read in the update call.
         if (TextAutosizer* textAutosizer = mainFrame()->document()->textAutosizer())
             textAutosizer->updatePageInfoInAllFrames();
     }
 }
 
 void VisualViewport::reset()
@@ skipping 145 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());
 
         // 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);
+        initializeScrollbars();
     }
 
     m_innerViewportScrollLayer->removeAllChildren();
     m_innerViewportScrollLayer->addChild(currentLayerTreeRoot);
 }
 
+void VisualViewport::initializeScrollbars()
+{
+    if (visualViewportSuppliesScrollbars()) {
+        if (!m_overlayScrollbarHorizontal->parent())
+            m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
+        if (!m_overlayScrollbarVertical->parent())
+            m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
+    } else {
+        m_overlayScrollbarHorizontal->removeFromParent();
+        m_overlayScrollbarVertical->removeFromParent();
+    }
+
+    setupScrollbar(WebScrollbar::Horizontal);
+    setupScrollbar(WebScrollbar::Vertical);
+}
+
 void VisualViewport::setupScrollbar(WebScrollbar::Orientation orientation)
 {
     bool isHorizontal = orientation == WebScrollbar::Horizontal;
     GraphicsLayer* scrollbarGraphicsLayer = isHorizontal ?
         m_overlayScrollbarHorizontal.get() : m_overlayScrollbarVertical.get();
     OwnPtr<WebScrollbarLayer>& webScrollbarLayer = isHorizontal ?
         m_webOverlayScrollbarHorizontal : m_webOverlayScrollbarVertical;
 
-    int thumbThickness = frameHost().settings().pinchOverlayScrollbarThickness();
-    int scrollbarThickness = thumbThickness;
-    int scrollbarMargin = scrollbarThickness;
-
-    // FIXME: Rather than manually creating scrollbar layers, we should create
-    // real scrollbars so we can reuse all the machinery from ScrollbarTheme.
-#if OS(ANDROID)
-    thumbThickness = ScrollbarTheme::theme()->thumbThickness(0);
-    scrollbarThickness = ScrollbarTheme::theme()->scrollbarThickness(RegularScrollbar);
-    scrollbarMargin = ScrollbarTheme::theme()->scrollbarMargin();
-#endif
+    ScrollbarTheme* theme = ScrollbarThemeOverlay::mobileTheme();
+    int thumbThickness = theme->thumbThickness(0);
+    int scrollbarThickness = theme->scrollbarThickness(RegularScrollbar);
+    int scrollbarMargin = theme->scrollbarMargin();
 
     if (!webScrollbarLayer) {
         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