sandbox: Change directory names in ProcUtil test to support Android

sandbox/linux/services/proc_util_unittest.cc

Index: sandbox/linux/services/proc_util_unittest.cc
diff --git a/sandbox/linux/services/proc_util_unittest.cc b/sandbox/linux/services/proc_util_unittest.cc
index ee36c8343d77c56c37394a7fcd3a17a19fdb3338..54747d8c6995f8292bceec7579642bee93741787 100644
--- a/sandbox/linux/services/proc_util_unittest.cc
+++ b/sandbox/linux/services/proc_util_unittest.cc
@@ -28,9 +28,9 @@ TEST(ProcUtil, HasOpenDirectory) {
   // No open directory should exist at startup.
   EXPECT_FALSE(ProcUtil::HasOpenDirectory(-1));
   {
-    // Have a "/dev" file descriptor around.
-    int dev_fd = open("/dev", O_RDONLY | O_DIRECTORY);
-    base::ScopedFD dev_fd_closer(dev_fd);
+    // Have a "/proc" file descriptor around.
+    int proc_fd = open("/proc", O_RDONLY | O_DIRECTORY);
+    base::ScopedFD proc_fd_closer(proc_fd);
     EXPECT_TRUE(ProcUtil::HasOpenDirectory(-1));
   }
   EXPECT_FALSE(ProcUtil::HasOpenDirectory(-1));
@@ -48,14 +48,14 @@ TEST(ProcUtil, HasOpenDirectoryWithFD) {
   EXPECT_FALSE(ProcUtil::HasOpenDirectory(proc_fd));
 
   {
-    // Have a "/dev" file descriptor around.
-    int dev_fd = open("/dev", O_RDONLY | O_DIRECTORY);
-    base::ScopedFD dev_fd_closer(dev_fd);
+    // Have a "/proc/self" file descriptor around.

[jln (very slow on Chromium), 2015/02/19 00:47:21]

It's a little confusing to use /proc/self/ given that there is also a |proc_fd|.

How about /sys/ or /proc/sys/, would that work?

[leecam, 2015/02/20 00:27:43]

Yeah at the moment but nnk is working to lock down /proc further so you can only
get to /proc/X where X is a pid in the same container or 'self'. So I picked
/proc/self as I think it would be safest thing for the future... 

[jln (very slow on Chromium), 2015/02/20 01:14:14]

Maybe rename the variable from "proc_self_fd" to "open_directory_fd" and simply
say "Have a directory file descriptor around" in the comment for the function?

+    int proc_self_fd = open("/proc/self", O_RDONLY | O_DIRECTORY);
+    base::ScopedFD proc_self_fd_closer(proc_self_fd);
     EXPECT_TRUE(ProcUtil::HasOpenDirectory(proc_fd));
   }
 
-  // The "/dev" file descriptor should now be closed, |proc_fd| is the only
-  // directory file descriptor open.
+  // The "/proc/self" file descriptor should now be closed, |proc_fd| is the
+  // only directory file descriptor open.
   EXPECT_FALSE(ProcUtil::HasOpenDirectory(proc_fd));
 }