Don't crash when resource path isn't specified

tests/ColorSpaceTest.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Resources.h"
 #include "SkCodec.h"
 #include "SkColorSpace.h"
@@ skipping 39 matching lines @@
     REPORTER_ASSERT(r, almost_equal(0.0970764f, xyz.fMat[5]));
     REPORTER_ASSERT(r, almost_equal(0.143066f, xyz.fMat[6]));
     REPORTER_ASSERT(r, almost_equal(0.0606079f, xyz.fMat[7]));
     REPORTER_ASSERT(r, almost_equal(0.714096f, xyz.fMat[8]));
 #endif
 }
 
 DEF_TEST(ColorSpaceParseJpegICCProfile, r) {
     SkAutoTDelete<SkStream> stream(resource("icc-v2-gbr.jpg"));
     REPORTER_ASSERT(r, nullptr != stream);
+    if (!stream) {
+        return;
+    }
 
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
     REPORTER_ASSERT(r, nullptr != codec);
+    if (!codec) {
+        return;
+    }
 
     SkColorSpace* colorSpace = codec->getColorSpace();
     REPORTER_ASSERT(r, nullptr != colorSpace);
 
     // It's important to use almost equal here.  This profile sets gamma as
     // 563 / 256, which actually comes out to about 2.19922.
     SkFloat3 gammas = colorSpace->gamma();
     REPORTER_ASSERT(r, almost_equal(2.2f, gammas.fVec[0]));
     REPORTER_ASSERT(r, almost_equal(2.2f, gammas.fVec[1]));
     REPORTER_ASSERT(r, almost_equal(2.2f, gammas.fVec[2]));
 
     // These nine values were extracted from the color profile.  Until we know any
     // better, we'll assume these are the right values and test that we continue
     // to extract them properly.
     SkFloat3x3 xyz = colorSpace->xyz();
     REPORTER_ASSERT(r, almost_equal(0.385117f, xyz.fMat[0]));
     REPORTER_ASSERT(r, almost_equal(0.716904f, xyz.fMat[1]));
     REPORTER_ASSERT(r, almost_equal(0.0970612f, xyz.fMat[2]));
     REPORTER_ASSERT(r, almost_equal(0.143051f, xyz.fMat[3]));
     REPORTER_ASSERT(r, almost_equal(0.0606079f, xyz.fMat[4]));
     REPORTER_ASSERT(r, almost_equal(0.713913f, xyz.fMat[5]));
     REPORTER_ASSERT(r, almost_equal(0.436035f, xyz.fMat[6]));
     REPORTER_ASSERT(r, almost_equal(0.222488f, xyz.fMat[7]));
     REPORTER_ASSERT(r, almost_equal(0.013916f, xyz.fMat[8]));
 }