Merge CompositedScrollingForFrames into PreferCompositingToLCDText

Source/core/rendering/compositing/CompositingReasonFinder.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/rendering/compositing/CompositingReasonFinder.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/dom/Document.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/page/Page.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 
 namespace blink {
 
 CompositingReasonFinder::CompositingReasonFinder(RenderView& renderView)
     : m_renderView(renderView)
     , m_compositingTriggers(static_cast<CompositingTriggerFlags>(AllCompositingTriggers))
 {
     updateTriggers();
 }
 
 void CompositingReasonFinder::updateTriggers()
 {
     m_compositingTriggers = 0;
 
     Settings& settings = m_renderView.document().page()->settings();
-    if (settings.compositedScrollingForFramesEnabled())
+    if (settings.preferCompositingToLCDTextEnabled()) {
         m_compositingTriggers |= ScrollableInnerFrameTrigger;
+        m_compositingTriggers |= ViewportConstrainedPositionedTrigger;
+    }
 
     // We map both these settings to universal overlow scrolling.
     // FIXME: Replace these settings with a generic compositing setting for HighDPI.
     if (settings.acceleratedCompositingForOverflowScrollEnabled() || settings.compositorDrivenAcceleratedScrollingEnabled())
         m_compositingTriggers |= OverflowScrollTrigger;
-
-    if (settings.preferCompositingToLCDTextEnabled())
-        m_compositingTriggers |= ViewportConstrainedPositionedTrigger;
 }
 
 bool CompositingReasonFinder::hasOverflowScrollTrigger() const
 {
     return m_compositingTriggers & OverflowScrollTrigger;
 }
 
 bool CompositingReasonFinder::isMainFrame() const
 {
     // FIXME: LocalFrame::isMainFrame() is probably better.
@@ skipping 119 matching lines @@
 bool CompositingReasonFinder::requiresCompositingForPositionFixed(const RenderLayer* layer) const
 {
     if (!(m_compositingTriggers & ViewportConstrainedPositionedTrigger))
         return false;
     // Don't promote fixed position elements that are descendants of a non-view container, e.g. transformed elements.
     // They will stay fixed wrt the container rather than the enclosing frame.
     return layer->scrollsWithViewport() && m_renderView.frameView()->isScrollable();
 }
 
 }