fix valgrind

src/pathops/SkPathOpsOp.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkAddIntersections.h"
 #include "SkOpCoincidence.h"
 #include "SkOpEdgeBuilder.h"
 #include "SkPathOpsCommon.h"
@@ skipping 89 matching lines @@
 
 static bool bridgeOp(SkTDArray<SkOpContour* >& contourList, const SkPathOp op,
         const int xorMask, const int xorOpMask, SkPathWriter* simple, SkChunkAlloc* allocator) {
     bool firstContour = true;
     bool unsortable = false;
     bool topUnsortable = false;
     bool firstPass = true;
     SkPoint lastTopLeft;
     SkPoint topLeft = {SK_ScalarMin, SK_ScalarMin};
     do {
-        SkOpSpanBase* start;
-        SkOpSpanBase* end;
+        SkOpSpanBase* start = NULL;
+        SkOpSpanBase* end = NULL;
         bool topDone;
         bool onlyVertical = false;
         lastTopLeft = topLeft;
         SkOpSegment* current = FindSortableTop(contourList, firstPass, SkOpAngle::kBinarySingle,
                 &firstContour, &start, &end, &topLeft, &topUnsortable, &topDone, &onlyVertical,
                 allocator);
         if (!current) {
             if ((!topUnsortable || firstPass) && !topDone) {
                 SkASSERT(topLeft.fX != SK_ScalarMin && topLeft.fY != SK_ScalarMin);
                 if (lastTopLeft.fX == SK_ScalarMin && lastTopLeft.fY == SK_ScalarMin) {
@@ skipping 221 matching lines @@
     {  // if some edges could not be resolved, assemble remaining fragments
         SkPath temp;
         temp.setFillType(fillType);
         SkPathWriter assembled(temp);
         Assemble(wrapper, &assembled);
         *result = *assembled.nativePath();
         result->setFillType(fillType);
     }
     return true;
 }