Fixes a crash when xdg_mime library is unable to handle a long file path....

net/base/mime_util.cc

Index: net/base/mime_util.cc
===================================================================
--- net/base/mime_util.cc	(revision 52038)
+++ net/base/mime_util.cc	(working copy)
@@ -138,6 +138,11 @@
 
 bool MimeUtil::GetMimeTypeFromExtension(const FilePath::StringType& ext,
                                         string* result) const {
+  // Fixes a crash when xdg_mime library is unable to handle a long file path.
+  const unsigned kMaxFilePathSize = 65536;
+  if (ext.length() > kMaxFilePathSize)
+    return false;
+
   // We implement the same algorithm as Mozilla for mapping a file extension to
   // a mime type.  That is, we first check a hard-coded list (that cannot be
   // overridden), and then if not found there, we defer to the system registry.