Remove RenderLayer::m_hasUnclippedDescendant

No one reads this state.

Review URL: https://codereview.chromium.org/310543002

git-svn-id: svn://svn.chromium.org/blink/trunk@175204 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/rendering/RenderLayer.cpp

@@ -111,7 +111,6 @@ RenderLayer::RenderLayer(RenderLayerModelObject* renderer, LayerType type)
     , m_hasSelfPaintingLayerDescendantDirty(false)
     , m_hasOutOfFlowPositionedDescendant(false)
     , m_hasOutOfFlowPositionedDescendantDirty(true)
-    , m_hasUnclippedDescendant(false)
     , m_isUnclippedDescendant(false)
     , m_isRootLayer(renderer->isRenderView())
     , m_usedTransparency(false)
@@ -369,10 +368,6 @@ void RenderLayer::dirtyAncestorChainHasOutOfFlowPositionedDescendantStatus()
     for (RenderLayer* layer = this; layer; layer = layer->parent()) {
         layer->setHasOutOfFlowPositionedDescendantDirty(true);
 
-        // We may or may not have an unclipped descendant. If we do, we'll reset
-        // this to true the next time composited scrolling state is updated.
-        layer->setHasUnclippedDescendant(false);
-
         // If we have reached an out of flow positioned layer, we know our parent should have an out-of-flow positioned descendant.
         // In this case, there is no need to dirty our ancestors further.
         if (layer->renderer()->isOutOfFlowPositioned()) {
@@ -807,9 +802,9 @@ void RenderLayer::setAncestorChainHasVisibleDescendant()
     }
 }
 
-void RenderLayer::updateHasUnclippedDescendant()
+void RenderLayer::updateIsUnclippedDescendant()
 {
-    TRACE_EVENT0("blink_rendering", "RenderLayer::updateHasUnclippedDescendant");
+    TRACE_EVENT0("blink_rendering", "RenderLayer::updateIsUnclippedDescendant");
     ASSERT(renderer()->isOutOfFlowPositioned());
     if (!m_hasVisibleContent && !m_hasVisibleDescendant)
         return;
@@ -818,8 +813,9 @@ void RenderLayer::updateHasUnclippedDescendant()
     if (!frameView)
         return;
 
-    const RenderObject* containingBlock = renderer()->containingBlock();
     setIsUnclippedDescendant(false);
+
+    const RenderObject* containingBlock = renderer()->containingBlock();
     for (RenderLayer* ancestor = parent(); ancestor && ancestor->renderer() != containingBlock; ancestor = ancestor->parent()) {
         // TODO(vollick): This isn't quite right. Whenever ancestor is composited and clips
         // overflow, we're technically unclipped. However, this will currently cause a huge
@@ -828,9 +824,10 @@ void RenderLayer::updateHasUnclippedDescendant()
         // compositor, we will be able to relax this restriction without it being prohibitively
         // expensive (currently, we have to do a lot of work in the compositor to honor a
         // clip child/parent relationship).
-        if (ancestor->scrollsOverflow())
+        if (ancestor->scrollsOverflow()) {
             setIsUnclippedDescendant(true);
-        ancestor->setHasUnclippedDescendant(true);
+            return;
+        }
     }
 }
 
@@ -3749,12 +3746,6 @@ void RenderLayer::updateOutOfFlowPositioned(const RenderStyle* oldStyle)
     if (!wasOutOfFlowPositioned && !isOutOfFlowPositioned)
         return;
 
-    // Even if the layer remains out-of-flow, a change to this property
-    // will likely change its containing block. We must clear these bits
-    // so that they can be set properly by the RenderLayerCompositor.
-    for (RenderLayer* ancestor = parent(); ancestor; ancestor = ancestor->parent())
-        ancestor->setHasUnclippedDescendant(false);
-
     // Ensures that we reset the above bits correctly.
     compositor()->setNeedsUpdateCompositingRequirementsState();
 

third_party/WebKit/Source/core/rendering/RenderLayer.h

@@ -212,13 +212,10 @@ public:
     void setHasOutOfFlowPositionedDescendant(bool hasDescendant) { m_hasOutOfFlowPositionedDescendant = hasDescendant; }
     void setHasOutOfFlowPositionedDescendantDirty(bool dirty) { m_hasOutOfFlowPositionedDescendantDirty = dirty; }
 
-
-    bool hasUnclippedDescendant() const { return m_hasUnclippedDescendant; }
-    void setHasUnclippedDescendant(bool hasDescendant) { m_hasUnclippedDescendant = hasDescendant; }
-    void updateHasUnclippedDescendant();
+    void updateIsUnclippedDescendant();
     bool isUnclippedDescendant() const { return m_isUnclippedDescendant; }
 
-    // Will ensure that hasUnclippedDescendant and hasNonCompositiedChild are up to date.
+    // Will ensure that hasNonCompositiedChild are up to date.
     void updateScrollingStateAfterCompositingChange();
     bool hasVisibleNonLayerContent() const { return m_hasVisibleNonLayerContent; }
     bool hasNonCompositedChild() const { ASSERT(isAllowedToQueryCompositingState()); return m_hasNonCompositedChild; }
@@ -643,12 +640,6 @@ private:
     unsigned m_hasOutOfFlowPositionedDescendant : 1;
     unsigned m_hasOutOfFlowPositionedDescendantDirty : 1;
 
-    // This is true if we have an out-of-flow positioned descendant whose
-    // containing block is our ancestor. If this is the case, the descendant
-    // may fall outside of our clip preventing things like opting into
-    // composited scrolling (which causes clipping of all descendants).
-    unsigned m_hasUnclippedDescendant : 1;
-
     unsigned m_isUnclippedDescendant : 1;
 
     const unsigned m_isRootLayer : 1;

third_party/WebKit/Source/core/rendering/compositing/RenderLayerCompositor.cpp

@@ -240,7 +240,7 @@ void RenderLayerCompositor::updateCompositingRequirementsState()
         return;
 
     for (HashSet<RenderLayer*>::iterator it = m_outOfFlowPositionedLayers.begin(); it != m_outOfFlowPositionedLayers.end(); ++it)
-        (*it)->updateHasUnclippedDescendant();
+        (*it)->updateIsUnclippedDescendant();
 }
 
 static RenderVideo* findFullscreenVideoRenderer(Document& document)