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

content/browser/frame_host/navigation_entry_impl.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.
 
 #include "content/browser/frame_host/navigation_entry_impl.h"
 
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/common/content_constants.h"
@@ skipping 274 matching lines @@
   http_status_code_ = http_status_code;
 }
 
 int NavigationEntryImpl::GetHttpStatusCode() const {
   return http_status_code_;
 }
 
 void NavigationEntryImpl::SetRedirectChain(
     const std::vector<GURL>& redirect_chain) {
   redirect_chain_ = redirect_chain;
+
+  size_t total_size = 0;
+  for (size_t i = 0; i < redirect_chain_.size(); ++i) {
+    total_size += redirect_chain_[i].Bytesize();
+  }
+  UMA_HISTOGRAM_COUNTS("Navigation.RedirectChainSizeInBytes", total_size);
 }
 
 const std::vector<GURL>& NavigationEntryImpl::GetRedirectChain() const {
   return redirect_chain_;
 }
 
 bool NavigationEntryImpl::IsRestored() const {
   return restore_type_ != RESTORE_NONE;
 }
 
@@ skipping 45 matching lines @@
 }
 
 void NavigationEntryImpl::SetScreenshotPNGData(
     scoped_refptr<base::RefCountedBytes> png_data) {
   screenshot_ = png_data;
   if (screenshot_.get())
     UMA_HISTOGRAM_MEMORY_KB("Overscroll.ScreenshotSize", screenshot_->size());
 }
 
 }  // namespace content