Hoist compositorDrivenAcceleratedScrollingEnabled check out of scrollParent

Source/core/rendering/compositing/CompositingReasonFinder.cpp

Index: Source/core/rendering/compositing/CompositingReasonFinder.cpp
diff --git a/Source/core/rendering/compositing/CompositingReasonFinder.cpp b/Source/core/rendering/compositing/CompositingReasonFinder.cpp
index 6f9ae626c35aa7cd735e75bf78d1f9c5a653df8d..261c935086b1f604dd45728f3c6494711ab0d42f 100644
--- a/Source/core/rendering/compositing/CompositingReasonFinder.cpp
+++ b/Source/core/rendering/compositing/CompositingReasonFinder.cpp
@@ -59,52 +59,6 @@ bool CompositingReasonFinder::isMainFrame() const
     return !m_renderView.document().ownerElement();
 }
 
-CompositingReasons CompositingReasonFinder::styleDeterminedReasons(RenderObject* renderer) const
-{
-    CompositingReasons directReasons = CompositingReasonNone;
-
-    if (requiresCompositingForTransform(renderer))
-        directReasons |= CompositingReason3DTransform;
-
-    if (requiresCompositingForBackfaceVisibilityHidden(renderer))
-        directReasons |= CompositingReasonBackfaceVisibilityHidden;
-
-    if (requiresCompositingForFilters(renderer))
-        directReasons |= CompositingReasonFilters;
-
-    if (requiresCompositingForWillChange(renderer))
-        directReasons |= CompositingReasonWillChange;
-
-    ASSERT(!(directReasons & ~CompositingReasonComboAllStyleDeterminedReasons));
-    return directReasons;
-}
-
-CompositingReasons CompositingReasonFinder::nonStyleDeterminedDirectReasons(const RenderLayer* layer, bool* needToRecomputeCompositingRequirements) const
-{
-    CompositingReasons directReasons = CompositingReasonNone;
-    RenderObject* renderer = layer->renderer();
-
-    if (requiresCompositingForAnimation(renderer))
-        directReasons |= CompositingReasonActiveAnimation;
-
-    if (requiresCompositingForOutOfFlowClipping(layer))
-        directReasons |= CompositingReasonOutOfFlowClipping;
-
-    if (requiresCompositingForOverflowScrolling(layer))
-        directReasons |= CompositingReasonOverflowScrollingTouch;
-
-    if (requiresCompositingForOverflowScrollingParent(layer))
-        directReasons |= CompositingReasonOverflowScrollingParent;
-
-    if (requiresCompositingForPosition(renderer, layer, 0, needToRecomputeCompositingRequirements))
-        directReasons |= renderer->style()->position() == FixedPosition ? CompositingReasonPositionFixed : CompositingReasonPositionSticky;
-
-    directReasons |= renderer->additionalCompositingReasons(m_compositingTriggers);
-
-    ASSERT(!(directReasons & CompositingReasonComboAllStyleDeterminedReasons));
-    return directReasons;
-}
-
 CompositingReasons CompositingReasonFinder::directReasons(const RenderLayer* layer, bool* needToRecomputeCompositingRequirements) const
 {
     CompositingReasons styleReasons = layer->styleDeterminedCompositingReasons();
@@ -112,6 +66,7 @@ CompositingReasons CompositingReasonFinder::directReasons(const RenderLayer* lay
     return styleReasons | nonStyleDeterminedDirectReasons(layer, needToRecomputeCompositingRequirements);
 }
 
+// This information doesn't appear to be incorporated into CompositingReasons.
 bool CompositingReasonFinder::requiresCompositingForScrollableFrame() const
 {
     // Need this done first to determine overflow.
@@ -126,15 +81,34 @@ bool CompositingReasonFinder::requiresCompositingForScrollableFrame() const
     return frameView->isScrollable();
 }
 
+CompositingReasons CompositingReasonFinder::styleDeterminedReasons(RenderObject* renderer) const
+{
+    CompositingReasons directReasons = CompositingReasonNone;
+
+    if (requiresCompositingForTransform(renderer))
+        directReasons |= CompositingReason3DTransform;
+
+    if (requiresCompositingForBackfaceVisibilityHidden(renderer))
+        directReasons |= CompositingReasonBackfaceVisibilityHidden;
+
+    if (requiresCompositingForFilters(renderer))
+        directReasons |= CompositingReasonFilters;
+
+    if (requiresCompositingForWillChange(renderer))
+        directReasons |= CompositingReasonWillChange;
+
+    ASSERT(!(directReasons & ~CompositingReasonComboAllStyleDeterminedReasons));
+    return directReasons;
+}
+
 bool CompositingReasonFinder::requiresCompositingForTransform(RenderObject* renderer) const
 {
     if (!(m_compositingTriggers & ThreeDTransformTrigger))
         return false;
 
-    RenderStyle* style = renderer->style();
     // Note that we ask the renderer if it has a transform, because the style may have transforms,
     // but the renderer may be an inline that doesn't suppport them.
-    return renderer->hasTransform() && style->transform().has3DOperation();
+    return renderer->hasTransform() && renderer->style()->transform().has3DOperation();
 }
 
 bool CompositingReasonFinder::requiresCompositingForBackfaceVisibilityHidden(RenderObject* renderer) const
@@ -145,41 +119,74 @@ bool CompositingReasonFinder::requiresCompositingForBackfaceVisibilityHidden(Ren
     return renderer->style()->backfaceVisibility() == BackfaceVisibilityHidden;
 }
 
-bool CompositingReasonFinder::requiresCompositingForAnimation(RenderObject* renderer) const
+bool CompositingReasonFinder::requiresCompositingForFilters(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & AnimationTrigger))
+    if (!(m_compositingTriggers & FilterTrigger))
         return false;
 
-    return shouldCompositeForActiveAnimations(*renderer);
+    return renderer->hasFilter();
 }
 
-bool CompositingReasonFinder::requiresCompositingForFilters(RenderObject* renderer) const
+bool CompositingReasonFinder::requiresCompositingForWillChange(const RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & FilterTrigger))
+    if (renderer->style()->hasWillChangeCompositingHint())
+        return true;
+
+    if (!(m_compositingTriggers & GPURasterizationTrigger))
         return false;
 
-    return renderer->hasFilter();
+    return renderer->style()->hasWillChangeGpuRasterizationHint();
 }
 
-bool CompositingReasonFinder::requiresCompositingForOverflowScrollingParent(const RenderLayer* layer) const
+CompositingReasons CompositingReasonFinder::nonStyleDeterminedDirectReasons(const RenderLayer* layer, bool* needToRecomputeCompositingRequirements) const
 {
-    return !!layer->scrollParent();
+    CompositingReasons directReasons = CompositingReasonNone;
+    RenderObject* renderer = layer->renderer();
+
+    if (requiresCompositingForAnimation(renderer))
+        directReasons |= CompositingReasonActiveAnimation;
+
+    if (m_renderView.compositorDrivenAcceleratedScrollingEnabled()) {
+        if (requiresCompositingForOutOfFlowClipping(layer))
+            directReasons |= CompositingReasonOutOfFlowClipping;
+
+        if (requiresCompositingForOverflowScrollingParent(layer))
+            directReasons |= CompositingReasonOverflowScrollingParent;
+    }
+
+    if (requiresCompositingForOverflowScrolling(layer))
+        directReasons |= CompositingReasonOverflowScrollingTouch;
+
+    if (requiresCompositingForPosition(renderer, layer, 0, needToRecomputeCompositingRequirements))
+        directReasons |= renderer->style()->position() == FixedPosition ? CompositingReasonPositionFixed : CompositingReasonPositionSticky;
+
+    directReasons |= renderer->additionalCompositingReasons(m_compositingTriggers);
+
+    ASSERT(!(directReasons & CompositingReasonComboAllStyleDeterminedReasons));
+    return directReasons;
 }
 
-bool CompositingReasonFinder::requiresCompositingForOutOfFlowClipping(const RenderLayer* layer) const
+bool CompositingReasonFinder::requiresCompositingForAnimation(RenderObject* renderer) const
 {
-    return m_renderView.compositorDrivenAcceleratedScrollingEnabled() && layer->isUnclippedDescendant();
+    if (!(m_compositingTriggers & AnimationTrigger))
+        return false;
+
+    return shouldCompositeForActiveAnimations(*renderer);
 }
 
-bool CompositingReasonFinder::requiresCompositingForWillChange(const RenderObject* renderer) const
+bool CompositingReasonFinder::requiresCompositingForOutOfFlowClipping(const RenderLayer* layer) const
 {
-    if (renderer->style()->hasWillChangeCompositingHint())
-        return true;
+    return layer->isUnclippedDescendant();
+}
 
-    if (!(m_compositingTriggers & GPURasterizationTrigger))
-        return false;
+bool CompositingReasonFinder::requiresCompositingForOverflowScrollingParent(const RenderLayer* layer) const
+{
+    return layer->scrollParent();
+}
 
-    return renderer->style()->hasWillChangeGpuRasterizationHint();
+bool CompositingReasonFinder::requiresCompositingForOverflowScrolling(const RenderLayer* layer) const
+{
+    return layer->needsCompositedScrolling();
 }
 
 bool CompositingReasonFinder::isViewportConstrainedFixedOrStickyLayer(const RenderLayer* layer)
@@ -302,9 +309,4 @@ bool CompositingReasonFinder::requiresCompositingForPosition(RenderObject* rende
     return true;
 }
 
-bool CompositingReasonFinder::requiresCompositingForOverflowScrolling(const RenderLayer* layer) const
-{
-    return layer->needsCompositedScrolling();
-}
-
 }