Issue 224 - add Tell method to Minidump class. r=mento

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@235 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/google_breakpad/processor/minidump.h

@@ -804,6 +804,9 @@ class Minidump {
   // Sets the position of the minidump file to offset.
   bool SeekSet(off_t offset);
 
+  // Returns the current position of the minidump file.
+  off_t Tell() { return valid_ ? lseek(fd_, 0, SEEK_CUR) : (off_t)-1; }
+
   // The next 2 methods are medium-level I/O routines.
 
   // ReadString returns a string which is owned by the caller!  offset