Added root deletion code to fix valgrind error

src/core/SkQuadTree.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkQuadTree.h"
 #include "SkTSort.h"
 #include <stdio.h>
@@ skipping 173 matching lines @@
     return new SkQuadTree(bounds);
 }
 
 SkQuadTree::SkQuadTree(const SkIRect& bounds)
     : fCount(0)
     , fRoot(SkNEW_ARGS(QuadTreeNode, (bounds))) {
     SkASSERT((bounds.width() * bounds.height()) > 0);
 }
 
 SkQuadTree::~SkQuadTree() {
+    SkDELETE(fRoot);
 }
 
 void SkQuadTree::insert(void* data, const SkIRect& bounds, bool) {
     if (bounds.isEmpty()) {
         SkASSERT(false);
         return;
     }
 
     QuadTreeNode::Data quadTreeData(bounds, data);
     fRoot->insert(quadTreeData);
@@ skipping 11 matching lines @@
 }
 
 int SkQuadTree::getDepth() const {
     return fRoot->getDepth();
 }
 
 void SkQuadTree::rewindInserts() {
     SkASSERT(fClient);
     fRoot->rewindInserts(fClient);
 }