Revert of Force SkPath::getConvexity() cache for thread safety.

src/core/SkRecords.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPathPriv.h"
 #include "SkRecords.h"
 
 namespace SkRecords {
     PreCachedPath::PreCachedPath(const SkPath& path) : SkPath(path) {
         this->updateBoundsCache();
-        (void)this->getConvexity();
 #if 0  // Disabled to see if we ever really race on this.  It costs time, chromium:496982.
         SkPathPriv::FirstDirection junk;
         (void)SkPathPriv::CheapComputeFirstDirection(*this, &junk);
 #endif
     }
 
     TypedMatrix::TypedMatrix(const SkMatrix& matrix) : SkMatrix(matrix) {
         (void)this->getType();
     }
 }