Enforce WARN_UNUSED_RESULT attribute on Windows

ui/gfx/icon_util_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/icon_util.h"
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
@@ skipping 11 matching lines @@
 static const char kLargeIconName[] = "icon_util/128_X_128_icon.ico";
 static const char kTempIconFilename[] = "temp_test_icon.ico";
 
 }  // namespace
 
 class IconUtilTest : public testing::Test {
  public:
   void SetUp() override {
     gfx::RegisterPathProvider();
     ASSERT_TRUE(PathService::Get(gfx::DIR_TEST_DATA, &test_data_directory_));
-    temp_directory_.CreateUniqueTempDir();
+    ASSERT_TRUE(temp_directory_.CreateUniqueTempDir());
   }
 
   static const int kSmallIconWidth = 16;
   static const int kSmallIconHeight = 16;
   static const int kLargeIconWidth = 128;
   static const int kLargeIconHeight = 128;
 
   // Given a file name for an .ico file and an image dimensions, this
   // function loads the icon and returns an HICON handle.
   HICON LoadIconFromFile(const base::FilePath& filename,
@@ skipping 380 matching lines @@
 }
 
 // This tests that kNumIconDimensionsUpToMediumSize has the correct value.
 TEST_F(IconUtilTest, TestNumIconDimensionsUpToMediumSize) {
   ASSERT_LE(IconUtil::kNumIconDimensionsUpToMediumSize,
             IconUtil::kNumIconDimensions);
   EXPECT_EQ(IconUtil::kMediumIconSize,
             IconUtil::kIconDimensions[
                 IconUtil::kNumIconDimensionsUpToMediumSize - 1]);
 }