Fix warnings that were exposed when running with SK_DEBUG enable on an optimized release build.

src/core/SkPath.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBuffer.h"
 #include "SkCubicClipper.h"
 #include "SkErrorInternals.h"
@@ skipping 2232 matching lines @@
 // only valid for a single contour
 struct Convexicator {
     Convexicator()
     : fPtCount(0)
     , fConvexity(SkPath::kConvex_Convexity)
     , fFirstDirection(SkPathPriv::kUnknown_FirstDirection)
     , fIsFinite(true)
     , fIsCurve(false) {
         fExpectedDir = kInvalid_DirChange;
         // warnings
+        fPriorPt.set(0,0);
         fLastPt.set(0, 0);
         fCurrPt.set(0, 0);
         fLastVec.set(0, 0);
         fFirstVec.set(0, 0);
 
         fDx = fDy = 0;
         fSx = fSy = kValueNeverReturnedBySign;
     }
 
     SkPath::Convexity getConvexity() const { return fConvexity; }
@@ skipping 962 matching lines @@
         }
     } while (!done);
     return SkToBool(tangents.count()) ^ isInverse;
 }
 
 int SkPath::ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
                                 SkScalar w, SkPoint pts[], int pow2) {
     const SkConic conic(p0, p1, p2, w);
     return conic.chopIntoQuadsPOW2(pts, pow2);
 }