Revert of Buffer 2 seconds of data in the ffmpeg demuxer.

third_party/WebKit/LayoutTests/http/tests/media/video-load-metadata-decode-error.cgi

 #!/usr/bin/perl -wT
 
 use strict;
 
 use CGI;
 use File::stat;
 
 my $query = new CGI;
 
 my $name = $query->param('name');
@@ skipping 12 matching lines @@
 print "Cache-Control: no-cache\n";
 print "Content-Length: " . $filesize . "\n";
 print "Content-Type: " . $type . "\n";
 
 print "\n";
 
 open FILE, $name or die;
 binmode FILE;
 my ($data, $n);
 my $total = 0;
-my $break = $filesize  * 3 / 4;
+my $break = $filesize / 4;
 my $string = "corrupt video";
 seek(FILE, 0, 0);
 
 while (($n = read FILE, $data, 1024) != 0) {
     print $data;
 
     $total += $n;
     if ($total >= $filesize) {
         last;
     }
     
     if ($total >= $break) {
         print $string;
         $total += length($string);
     }
 
 }
 close(FILE);