Deprecate GetDirectoryFromPath on non-Windows.

base/file_util.h

Index: base/file_util.h
diff --git a/base/file_util.h b/base/file_util.h
index ad36a7e1641ce496efd5dedc69699e18c3878a82..fbde3e739fb213117dbcb107e3240a7dcc06c85c 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -49,17 +49,6 @@ bool EndsWithSeparator(const FilePath& path);
 // exists. Returns true if |path| is an existing directory, false otherwise.
 bool EnsureEndsWithSeparator(FilePath* path);
 
-// Returns the directory component of a path, without the trailing
-// path separator, or an empty string on error. The function does not
-// check for the existence of the path, so if it is passed a directory
-// without the trailing \, it will interpret the last component of the
-// path as a file and chomp it. This does not support relative paths.
-// Examples:
-// path == "C:\pics\jojo.jpg",     returns "C:\pics"
-// path == "C:\Windows\system32\", returns "C:\Windows\system32"
-// path == "C:\Windows\system32",  returns "C:\Windows"
-std::wstring GetDirectoryFromPath(const std::wstring& path);
-
 // Appends new_ending to path, adding a separator between the two if necessary.
 void AppendToPath(std::wstring* path, const std::wstring& new_ending);