Add support for SVG Clip paths in HTML

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 100 matching lines @@
     , m_visibleContentStatusDirty(true)
     , m_hasVisibleContent(false)
     , m_visibleDescendantStatusDirty(false)
     , m_hasVisibleDescendant(false)
     , m_hasVisibleNonLayerContent(false)
     , m_isPaginated(false)
     , m_3DTransformedDescendantStatusDirty(true)
     , m_has3DTransformedDescendant(false)
     , m_containsDirtyOverlayScrollbars(false)
     , m_hasFilterInfo(false)
+    , m_hasClipPathInfo(false)
     , m_needsAncestorDependentCompositingInputsUpdate(true)
     , m_needsDescendantDependentCompositingInputsUpdate(true)
     , m_childNeedsCompositingInputsUpdate(true)
     , m_hasCompositingDescendant(false)
     , m_hasNonCompositedChild(false)
     , m_shouldIsolateCompositedDescendants(false)
     , m_lostGroupedMapping(false)
     , m_viewportConstrainedNotCompositedReason(NoNotCompositedReason)
     , m_renderer(renderer)
     , m_parent(0)
@@ skipping 24 matching lines @@
 }
 
 RenderLayer::~RenderLayer()
 {
     if (renderer()->frame() && renderer()->frame()->page()) {
         if (ScrollingCoordinator* scrollingCoordinator = renderer()->frame()->page()->scrollingCoordinator())
             scrollingCoordinator->willDestroyRenderLayer(this);
     }
 
     removeFilterInfoIfNeeded();
+    removeClipPathInfoIfNeeded();
 
     if (groupedMapping()) {
         DisableCompositingQueryAsserts disabler;
         groupedMapping()->removeRenderLayerFromSquashingGraphicsLayer(this);
         setGroupedMapping(0);
     }
 
     // Child layers will be deleted by their corresponding render objects, so
     // we don't need to delete them ourselves.
 
@@ skipping 3367 matching lines @@
 
 void RenderLayer::updateFilters(const RenderStyle* oldStyle, const RenderStyle* newStyle)
 {
     if (!newStyle->hasFilter() && (!oldStyle || !oldStyle->hasFilter()))
         return;
 
     updateOrRemoveFilterClients();
     updateOrRemoveFilterEffectRenderer();
 }
 
+void RenderLayer::updateClipPath(const RenderStyle* oldStyle, const RenderStyle* newStyle)
+{
+    if (!newStyle->clipPath() && (!oldStyle || !oldStyle->clipPath()))
+        return;
+
+    updateOrRemoveClipPathClients();
+}
+
+void RenderLayer::updateOrRemoveClipPathClients()
+{
+    if (!hasClipPath()) {
+        removeClipPathInfoIfNeeded();
+        return;
+    }
+
+    if (renderer()->style()->clipPath()->type() == ClipPathOperation::REFERENCE)
+        ensureClipPathInfo()->updateReferenceClipPathClients(renderer()->style()->clipPath());
+    else if (hasClipPathInfo())
+        clipPathInfo()->removeReferenceClipPathClients();
+}
+
 bool RenderLayer::attemptDirectCompositingUpdate(StyleDifference diff, const RenderStyle* oldStyle)
 {
     CompositingReasons oldPotentialCompositingReasonsFromStyle = m_potentialCompositingReasonsFromStyle;
     compositor()->updatePotentialCompositingReasonsFromStyle(this);
 
     // This function implements an optimization for transforms and opacity.
     // A common pattern is for a touchmove handler to update the transform
     // and/or an opacity of an element every frame while the user moves their
     // finger across the screen. The conditions below recognize when the
     // compositing state is set up to receive a direct transform or opacity
@@ skipping 65 matching lines @@
         updateReflectionInfo(oldStyle);
     }
 
     if (RuntimeEnabledFeatures::cssCompositingEnabled())
         m_blendInfo.updateBlendMode();
 
     updateDescendantDependentFlags();
 
     updateTransform(oldStyle, renderer()->style());
     updateFilters(oldStyle, renderer()->style());
+    updateClipPath(oldStyle, renderer()->style());
 
     setNeedsCompositingInputsUpdate();
 }
 
 bool RenderLayer::scrollsOverflow() const
 {
     if (RenderLayerScrollableArea* scrollableArea = this->scrollableArea())
         return scrollableArea->scrollsOverflow();
 
     return false;
@@ skipping 143 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif