Add full support for filesystem URLs.

net/base/mime_sniffer.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Detecting mime types is a tricky business because we need to balance
 // compatibility concerns with security issues.  Here is a survey of how other
 // browsers behave and then a description of how we intend to behave.
 //
 // HTML payload, no Content-Type header:
 // * IE 7: Render as HTML
@@ skipping 549 matching lines @@
   }
 
   return true;
 }
 
 bool ShouldSniffMimeType(const GURL& url, const std::string& mime_type) {
   static base::Histogram* should_sniff_counter(NULL);
   if (!should_sniff_counter)
     should_sniff_counter =
         UMASnifferHistogramGet("mime_sniffer.ShouldSniffMimeType2", 3);
   // We are willing to sniff the mime type for HTTP, HTTPS, and FTP

[eroman, 2012/02/15 06:07:13]

You should probably update this comment to match. Or even better, change it to
not repeat what the code is already saying.

[abarth-chromium, 2012/02/15 08:43:20]

Or just remove the comment.  I'm sorry to have added it since it's redundant
with the code below.  (I'd also change the code below to use the scheme
constants, which have existed now for a long time.)

[ericu, 2012/02/15 22:48:09]

I'll kill the comment and convert to the constants.

[ericu, 2012/02/16 01:42:56]

Actually, I don't think the constants I've been using are accessible from
/net/base.  Do you know of any that are?

   bool sniffable_scheme = url.is_empty() ||
                           url.SchemeIs("http") ||
                           url.SchemeIs("https") ||
                           url.SchemeIs("ftp") ||
-                          url.SchemeIsFile();
+                          url.SchemeIsFile() ||
+                          url.SchemeIsFileSystem();
   if (!sniffable_scheme) {
     should_sniff_counter->Add(1);
     return false;
   }
 
   static const char* kSniffableTypes[] = {
     // Many web servers are misconfigured to send text/plain for many
     // different types of content.
     "text/plain",
     // We want to sniff application/octet-stream for
@@ skipping 94 matching lines @@
   // Now we look in our large table of magic numbers to see if we can find
   // anything that matches the content.
   if (SniffForMagicNumbers(content, content_size,
                            &have_enough_content, result))
     return true;  // We've matched a magic number.  No more content needed.
 
   return have_enough_content;
 }
 
 }  // namespace net