Add a histogram for size of the memory used by redirect chain.

url/gurl.cc

 // Copyright 2013 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.
 
 #ifdef WIN32
 #include <windows.h>
 #else
 #include <pthread.h>
 #endif
 
@@ skipping 508 matching lines @@
   return true;
 }
 
 void GURL::Swap(GURL* other) {
   spec_.swap(other->spec_);
   std::swap(is_valid_, other->is_valid_);
   std::swap(parsed_, other->parsed_);
   inner_url_.swap(other->inner_url_);
 }
 
+size_t GURL::Bytesize() const {
+  return sizeof(*this) + spec_.size() +
+      (inner_url_ ? inner_url_->Bytesize() : 0);
+}
+
 std::ostream& operator<<(std::ostream& out, const GURL& url) {
   return out << url.possibly_invalid_spec();
 }