fix size_t/int warnings in pictures

src/core/SkMatrixClipStateMgr.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 "SkMatrixClipStateMgr.h"
 #include "SkPictureRecord.h"
 
@@ skipping 51 matching lines @@
         //      mgr->writeDeltaMat...
         //      *curMatID...
         //  }
         // Right now this optimization would throw off the testing harness.
         // TODO: right now we're writing out the delta matrix from the prior
         // matrix state. This is a side-effect of writing out the entire
         // clip stack and should be resolved when that is fixed.
         mgr->writeDeltaMat(*curMatID, curClip.fMatrixID);
         *curMatID = curClip.fMatrixID;
 
-        int offset = 0;
+        size_t offset = 0;
 
         switch (curClip.fClipType) {
         case kRect_ClipType:
             offset = mgr->getPicRecord()->recordClipRect(curClip.fGeom.fRRect.rect(),
                                                          curClip.fOp, curClip.fDoAA);
             break;
         case kRRect_ClipType:
             offset = mgr->getPicRecord()->recordClipRRect(curClip.fGeom.fRRect, curClip.fOp,
                                                          curClip.fDoAA);
             break;
@@ skipping 328 matching lines @@
 }
 
 int SkMatrixClipStateMgr::addMatToDict(const SkMatrix& mat) {
     if (mat.isIdentity()) {
         return kIdentityMatID;
     }
 
     *fMatrixDict.append() = mat;
     return fMatrixDict.count()-1;
 }