Add ability to create solid color scrollbars in ScrollingCoordinator.

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 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 16 matching lines @@
 
 #include "core/page/scrolling/ScrollingCoordinator.h"
 
 #include "RuntimeEnabledFeatures.h"
 #include "core/dom/Document.h"
 #include "core/dom/Node.h"
 #include "core/html/HTMLElement.h"
 #include "core/page/Frame.h"
 #include "core/page/FrameView.h"
 #include "core/page/Page.h"
+#include "core/page/Settings.h"
 #include "core/platform/PlatformWheelEvent.h"
 #include "core/platform/ScrollAnimator.h"
 #include "core/platform/ScrollbarTheme.h"
 #include "core/platform/chromium/TraceEvent.h"
 #include "core/platform/chromium/support/WebScrollbarImpl.h"
 #include "core/platform/chromium/support/WebScrollbarThemeGeometryNative.h"
 #include "core/platform/graphics/GraphicsLayer.h"
 #include "core/platform/graphics/IntRect.h"
 #include "core/platform/graphics/Region.h"
 #include "core/platform/graphics/transforms/TransformState.h"
@@ skipping 154 matching lines @@
 {
     ScrollbarTheme* theme = scrollbar->theme();
     WebKit::WebScrollbarThemePainter painter(theme, scrollbar);
     OwnPtr<WebKit::WebScrollbarThemeGeometry> geometry(WebKit::WebScrollbarThemeGeometryNative::create(theme));
 
     OwnPtr<WebScrollbarLayer> scrollbarLayer = adoptPtr(WebKit::Platform::current()->compositorSupport()->createScrollbarLayer(new WebKit::WebScrollbarImpl(scrollbar), painter, geometry.leakPtr()));
     GraphicsLayer::registerContentsLayer(scrollbarLayer->layer());
     return scrollbarLayer.release();
 }
 
+PassOwnPtr<WebScrollbarLayer> ScrollingCoordinator::createSolidColorScrollbarLayer(ScrollbarOrientation orientation, int thumbThickness)
+{
+    WebKit::WebScrollbar::Orientation webOrientation = (orientation == HorizontalScrollbar) ? WebKit::WebScrollbar::Horizontal : WebKit::WebScrollbar::Vertical;
+    OwnPtr<WebScrollbarLayer> scrollbarLayer = adoptPtr(WebKit::Platform::current()->compositorSupport()->createSolidColorScrollbarLayer(webOrientation, thumbThickness));
+    return scrollbarLayer.release();
+}
+
 static void detachScrollbarLayer(GraphicsLayer* scrollbarGraphicsLayer)
 {
     ASSERT(scrollbarGraphicsLayer);
 
     scrollbarGraphicsLayer->setContentsToPlatformLayer(0);
     scrollbarGraphicsLayer->setDrawsContent(true);
 }
 
 static void setupScrollbarLayer(GraphicsLayer* scrollbarGraphicsLayer, WebScrollbarLayer* scrollbarLayer, WebLayer* scrollLayer)
 {
@@ skipping 43 matching lines @@
 
     GraphicsLayer* scrollbarGraphicsLayer = orientation == HorizontalScrollbar ? horizontalScrollbarLayerForScrollableArea(scrollableArea) : verticalScrollbarLayerForScrollableArea(scrollableArea);
     if (scrollbarGraphicsLayer) {
         Scrollbar* scrollbar = orientation == HorizontalScrollbar ? scrollableArea->horizontalScrollbar() : scrollableArea->verticalScrollbar();
         if (scrollbar->isCustomScrollbar()) {
             detachScrollbarLayer(scrollbarGraphicsLayer);
             return;
         }
 
         WebScrollbarLayer* scrollbarLayer = getWebScrollbarLayer(scrollableArea, orientation);
-        if (!scrollbarLayer)
-            scrollbarLayer = addWebScrollbarLayer(scrollableArea, orientation, createScrollbarLayer(scrollbar));
+        if (!scrollbarLayer) {
+            Settings* settings = m_page->mainFrame()->document()->settings();
+
+            OwnPtr<WebScrollbarLayer> webScrollbarLayer;
+            if (settings->useSolidColorScrollbars()) {
+                ASSERT(settings->usesOverlayScrollbars());
+                webScrollbarLayer = createSolidColorScrollbarLayer(orientation, -1);
+            } else {
+                webScrollbarLayer = createScrollbarLayer(scrollbar);
+            }
+            scrollbarLayer = addWebScrollbarLayer(scrollableArea, orientation, webScrollbarLayer.release());
+        }
 
         // Root layer non-overlay scrollbars should be marked opaque to disable
         // blending.
         bool isOpaqueScrollbar = !scrollbar->isOverlayScrollbar();
         if (!scrollbarGraphicsLayer->contentsOpaque())
             scrollbarGraphicsLayer->setContentsOpaque(isMainFrame && isOpaqueScrollbar);
         scrollbarLayer->layer()->setOpaque(scrollbarGraphicsLayer->contentsOpaque());
 
         setupScrollbarLayer(scrollbarGraphicsLayer, scrollbarLayer, scrollingWebLayerForScrollableArea(scrollableArea));
     } else
@@ skipping 522 matching lines @@
         stringBuilder.resize(stringBuilder.length() - 2);
     return stringBuilder.toString();
 }
 
 String ScrollingCoordinator::mainThreadScrollingReasonsAsText() const
 {
     return mainThreadScrollingReasonsAsText(mainThreadScrollingReasons());
 }
 
 } // namespace WebCore