Put SVGResourceContainer subtypes into their own property trees.

third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h

 // Copyright 2015 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.
 
 #ifndef PaintPropertyTreeBuilder_h
 #define PaintPropertyTreeBuilder_h
 
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
 #include "platform/graphics/paint/EffectPaintPropertyNode.h"
@@ skipping 72 matching lines @@
   // clip. The cull rect for its input shall be derived from its output clip.
   // This variable represents the input cull of current effect, also serves as
   // output clip of child effects that don't have a hard clip.
   const ClipPaintPropertyNode* inputClipOfCurrentEffect;
 
   // True if a change has forced all properties in a subtree to be updated. This
   // can be set due to paint offset changes or when the structure of the
   // property tree changes (i.e., a node is added or removed).
   bool forceSubtreeUpdate;
 
-  PaintPropertyTreeBuilderContext()
-      : containerForAbsolutePosition(nullptr),
-        currentEffect(nullptr),
-        inputClipOfCurrentEffect(nullptr),
-        forceSubtreeUpdate(false) {}
+  // Initializes all property tree nodes to the roots.
+  PaintPropertyTreeBuilderContext();
 };
 
 // Creates paint property tree nodes for special things in the layout tree.
 // Special things include but not limit to: overflow clip, transform, fixed-pos,
 // animation, mask, filter, ... etc.
 // It expects to be invoked for each layout tree node in DOM order during
 // InPrePaint phase.
 class PaintPropertyTreeBuilder {
  public:
   void setupInitialContext(PaintPropertyTreeBuilderContext&);
@@ skipping 49 matching lines @@
       const LayoutObject&,
       PaintPropertyTreeBuilderContext&);
   ALWAYS_INLINE static void updateOutOfFlowContext(
       const LayoutObject&,
       PaintPropertyTreeBuilderContext&);
 };
 
 }  // namespace blink
 
 #endif  // PaintPropertyTreeBuilder_h