Add histogram to measure string response size of URLFetcher.

content/common/net/url_fetcher_impl.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.
 
 #include "content/common/net/url_fetcher_impl.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util_proxy.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop_proxy.h"
+#include "base/metrics/histogram.h"
 #include "base/platform_file.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
 #include "base/threading/thread.h"
 #include "content/public/common/url_fetcher_delegate.h"
 #include "content/public/common/url_fetcher_factory.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
@@ skipping 1032 matching lines @@
 void URLFetcherImpl::ReceivedContentWasMalformed() {
   core_->ReceivedContentWasMalformed();
 }
 
 bool URLFetcherImpl::GetResponseAsString(
     std::string* out_response_string) const {
   if (core_->response_destination_ != STRING)
     return false;
 
   *out_response_string = core_->data_;
+  UMA_HISTOGRAM_MEMORY_KB("UrlFetcher.StringResponseSize",
+                          (core_->data_.length() / 1024));
+
   return true;
 }
 
 bool URLFetcherImpl::GetResponseAsFilePath(bool take_ownership,
                                            FilePath* out_response_path) const {
   DCHECK(core_->delegate_loop_proxy_->BelongsToCurrentThread());
   if (core_->response_destination_ != TEMP_FILE ||
       !core_->temp_file_writer_.get())
     return false;
 
@@ skipping 22 matching lines @@
 
 // static
 content::URLFetcherFactory* URLFetcherImpl::factory() {
   return g_factory;
 }
 
 // static
 void URLFetcherImpl::set_factory(content::URLFetcherFactory* factory) {
   g_factory = factory;
 }