diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/core/SkQuadTree.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/core/SkQuadTree.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,111 @@
+/*
+ * 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
+
+#include "SkRect.h"
+#include "SkTDArray.h"
+#include "SkBBoxHierarchy.h"
+#include "SkTInternalSList.h"
+#include "SkTObjectPool.h"
+
+/**
+ * A QuadTree implementation. In short, it is a tree containing a hierarchy of bounding rectangles
+ * in which each internal node has exactly four children.
+ *
+ * For more details see:
+ *
+ * http://en.wikipedia.org/wiki/Quadtree
+ */
+class SkQuadTree : public SkBBoxHierarchy {
+public:
+    SK_DECLARE_INST_COUNT(SkQuadTree)
+
+    /**
+     * Quad tree constructor.
+     * @param bounds The bounding box for the root of the quad tree.
+     *               giving the quad tree bounds that fall outside the root
+     *               bounds may result in pathological but correct behavior.
+     */
+    SkQuadTree(const SkIRect& bounds);
+
+    virtual ~SkQuadTree();
+
+    /**
+     * Insert a node, consisting of bounds and a data value into the tree, if we don't immediately
+     * need to use the tree; we may allow the insert to be deferred (this can allow us to bulk-load
+     * a large batch of nodes at once, which tends to be faster and produce a better tree).
+     *  @param data The data value
+     *  @param bounds The corresponding bounding box
+     *  @param defer Can this insert be deferred? (this may be ignored)
+     */
+    virtual void insert(void* data, const SkIRect& bounds, bool defer = false) SK_OVERRIDE;
+
+    /**
+     * If any inserts have been deferred, this will add them into the tree
+     */
+    virtual void flushDeferredInserts() SK_OVERRIDE;
+
+    /**
+     * Given a query rectangle, populates the passed-in array with the elements it intersects
+     */
+    virtual void search(const SkIRect& query, SkTDArray<void*>* results) SK_OVERRIDE;
+
+    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 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;
+    SkTInternalSList<Entry> fDeferred;
+
+    Node* pickChild(Node* node, const SkIRect& bounds) const;
+    void insert(Node* node, Entry* entry);
+    void search(Node* node, const SkIRect& query, SkTDArray<void*>* results) const;
+    void clear(Node* node);
+    int getDepth(Node* node) const;
+
+    typedef SkBBoxHierarchy INHERITED;
+};
+
+#endif