Some additions to support symlinks better on platforms that support them.

base/file_util_posix.cc

Index: base/file_util_posix.cc
diff --git a/base/file_util_posix.cc b/base/file_util_posix.cc
index e0a1a55e066738e8f1d9025324a4825e58d96c05..3fbc6d648aa6c02b6a628093292f9129e483ee64 100644
--- a/base/file_util_posix.cc
+++ b/base/file_util_posix.cc
@@ -373,6 +373,28 @@ bool ReadFromFD(int fd, char* buffer, size_t bytes) {
   return total_read == bytes;
 }
 
+bool CreateSymbolicLink(const FilePath& target_path,
+                        const FilePath& symlink_path) {
+  DCHECK(!symlink_path.empty());
+  DCHECK(!target_path.empty());
+  return ::symlink(target_path.value().c_str(),
+                   symlink_path.value().c_str()) != -1;
+}
+
+bool ReadSymbolicLink(const FilePath& symlink_path,
+                      FilePath* target_path) {
+  DCHECK(!symlink_path.empty());
+  DCHECK(target_path);
+  char buf[PATH_MAX];
+  ssize_t count = ::readlink(symlink_path.value().c_str(), buf, arraysize(buf));
+  if (count > 0) {

[Evan Martin, 2010/11/29 21:21:14]

Consider an early return pattern here instead (if (count <= 0) return false;)

[Greg Spencer (Chromium), 2010/11/29 21:34:11]

Done.

+    *target_path = FilePath(FilePath::StringType(buf, count));

[Evan Martin, 2010/11/29 21:21:14]

Can use std::string here, since we know the string type.

[Greg Spencer (Chromium), 2010/11/29 21:34:11]

I prefer to use the actual type that FilePath expects, actually.  I'm aware that
StringType is just a typedef for std::string on posix, but if that ever changed,
or this code were ported to other platforms, using the StringType here makes it
a lot easier to find instances that are supposed to be interpreted as FilePaths
as opposed to strings used for other purposes (i.e. it's more self documenting).

For this particular instance, this isn't a huge deal, but as a coding practice,
I think it is.

+  } else {
+    return false;
+  }
+  return true;
+}
+
 // Creates and opens a temporary file in |directory|, returning the
 // file descriptor. |path| is set to the temporary file path.
 // This function does NOT unlink() the file.