Slightly faster quadtree searching

src/core/SkQuadTree.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkQuadTree_DEFINED
 #define SkQuadTree_DEFINED
 
@@ skipping 48 matching lines @@
     virtual void clear() SK_OVERRIDE;
 
     /**
      * Gets the depth of the tree structure
      */
     virtual int getDepth() const SK_OVERRIDE;
 
     /**
      * This gets the insertion count (rather than the node count)
      */
-    virtual int getCount() const SK_OVERRIDE { return fEntryCount; }
+    virtual int getCount() const SK_OVERRIDE {
+        return fEntryPool.allocated() - fEntryPool.available();
+    }
 
     virtual void rewindInserts() SK_OVERRIDE;
 
 private:
     struct Entry {
         Entry() : fData(NULL) {}
         SkIRect fBounds;
         void* fData;
         SK_DECLARE_INTERNAL_SLIST_INTERFACE(Entry);
     };
 
     static const int kChildCount = 4;
 
     struct Node {
         Node() {
             for (int index=0; index<kChildCount; ++index) {
                 fChildren[index] = NULL;
             }
         }
         SkTInternalSList<Entry> fEntries;
         SkIRect fBounds;
         SkIPoint fSplitPoint; // Only valid if the node has children.
         Node* fChildren[kChildCount];
         SK_DECLARE_INTERNAL_SLIST_ADAPTER(Node, fChildren[0]);
     };
 
     SkTObjectPool<Entry> fEntryPool;
     SkTObjectPool<Node> fNodePool;
-    int fEntryCount;
     Node* fRoot;
+    SkIRect fRootBounds;
     SkTInternalSList<Entry> fDeferred;
 
-    Node* pickChild(Node* node, const SkIRect& bounds) const;
     void insert(Node* node, Entry* entry);
+    void split(Node* node);
     void search(Node* node, const SkIRect& query, SkTDArray<void*>* results) const;
     void clear(Node* node);
     int getDepth(Node* node) const;
 
     typedef SkBBoxHierarchy INHERITED;
 };
 
 #endif