Start cleaning up 64bit Win warnings

tools/skpdiff/skpdiff_util.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #if SK_BUILD_FOR_MAC || SK_BUILD_FOR_UNIX || SK_BUILD_FOR_ANDROID
 #   include <unistd.h>
 #   include <sys/time.h>
@@ skipping 112 matching lines @@
         if (!sk_isdir(joinedPath.c_str())) {
             entries->push_back(SkString(entry->d_name));
         }
     }
 
     closedir(dir);
 
     return true;
 #elif SK_BUILD_FOR_WIN32
     char pathDirGlob[MAX_PATH];
-    char pathLength = strlen(path);
+    size_t pathLength = strlen(path);
     strncpy(pathDirGlob, path, pathLength);
 
     if (path[pathLength - 1] == '/' || path[pathLength - 1] == '\\') {
         SkASSERT(pathLength + 2 <= MAX_PATH);
         pathDirGlob[pathLength] = '*';
         pathDirGlob[pathLength + 1] = '\0';
     } else {
         SkASSERT(pathLength + 3 <= MAX_PATH);
         pathDirGlob[pathLength] = '\\';
         pathDirGlob[pathLength + 1] = '*';
@@ skipping 53 matching lines @@
 #elif SK_BUILD_FOR_WIN32
     SkString fullPath(MAX_PATH);
     if (_fullpath(fullPath.writable_str(), path.c_str(), MAX_PATH) == NULL) {
         fullPath.reset();
     }
     return fullPath;
 #else
     return SkString();
 #endif
 }