Add base::ExecutableExistsInPath

base/files/file_util_unittest.cc

 // Copyright (c) 2012 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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <fstream>
 #include <set>
@@ skipping 820 matching lines @@
   FileEnumerator f2(subdir_path, true, FileEnumerator::FILES);
   FindResultCollector c2(&f2);
   EXPECT_TRUE(c2.HasFile(file_name));
   EXPECT_EQ(1, c2.size());
 
   // Delete the file.
   EXPECT_TRUE(DeleteFile(subdir_path, true));
   EXPECT_FALSE(PathExists(subdir_path));
 }
 
+TEST_F(FileUtilTest, ExecutableExistsInPath) {

[Tom (Use chromium acct), 2016/06/22 16:57:56]

Not much to it at this point...
Maybe it would be better to manually set the PATH here to 2 temp directories,
and add/remove some executable (and nonexecutable) files to test more
thoroughly?

+  EXPECT_TRUE(ExecutableExistsInPath("sh"));
+  EXPECT_FALSE(ExecutableExistsInPath("foobar"));
+}
+
 #endif  // defined(OS_POSIX)
 
 #if defined(OS_WIN)
 // Tests that the Delete function works for wild cards, especially
 // with the recursion flag.  Also coincidentally tests PathExists.
 // TODO(erikkay): see if anyone's actually using this feature of the API
 TEST_F(FileUtilTest, DeleteWildCard) {
   // Create a file and a directory
   FilePath file_name = temp_dir_.path().Append(FPL("Test DeleteWildCard.txt"));
   CreateTextFile(file_name, bogus_content);
@@ skipping 1727 matching lines @@
   // Trying to close it should crash. This is important for security.
   EXPECT_DEATH(CloseWithScopedFD(fds[1]), "");
 #endif
 }
 
 #endif  // defined(OS_POSIX)
 
 }  // namespace
 
 }  // namespace base