Use SkToBool to fix a warning.

tests/FrontBufferedStreamTest.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.
  */
 
 #include "SkFrontBufferedStream.h"
 #include "SkRefCnt.h"
 #include "SkStream.h"
@@ skipping 177 matching lines @@
 
 private:
     const bool fHasLength;
     const bool fHasPosition;
 };
 
 // Test all possible combinations of the wrapped stream having a length and a position.
 static void test_length_combos(skiatest::Reporter* reporter, size_t bufferSize) {
     for (int hasLen = 0; hasLen <= 1; hasLen++) {
         for (int hasPos = 0; hasPos <= 1; hasPos++) {
-            LengthOptionalStream stream((bool) hasLen, (bool) hasPos);
+            LengthOptionalStream stream(SkToBool(hasLen), SkToBool(hasPos));
             SkAutoTUnref<SkStream> buffered(SkFrontBufferedStream::Create(&stream, bufferSize));
             test_hasLength(reporter, *buffered.get(), stream);
         }
     }
 }
 
 // Test using a stream with an initial offset.
 static void test_initial_offset(skiatest::Reporter* reporter, size_t bufferSize) {
     SkMemoryStream memStream(gAbcs, strlen(gAbcs), false);
 
@@ skipping 33 matching lines @@
     test_length_combos(reporter, bufferSize);
     test_initial_offset(reporter, bufferSize);
 }
 
 DEF_TEST(FrontBufferedStream, reporter) {
     // Test 6 and 64, which are used by Android, as well as another arbitrary length.
     test_buffers(reporter, 6);
     test_buffers(reporter, 15);
     test_buffers(reporter, 64);
 }