Send compressed histograms with system logs when sending feedback.

chrome/browser/extensions/api/feedback_private/feedback_service_chromeos.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 "chrome/browser/extensions/api/feedback_private/feedback_service.h"
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
+#include "base/metrics/statistics_recorder.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/chromeos/system_logs/scrubbed_system_logs_fetcher.h"
 
 using extensions::api::feedback_private::SystemInformation;
 
 namespace extensions {
 
 class FeedbackServiceImpl
     : public FeedbackService,
       public base::SupportsWeakPtr<FeedbackServiceImpl> {
  public:
   FeedbackServiceImpl();
   virtual ~FeedbackServiceImpl();
 
   virtual std::string GetUserEmail() OVERRIDE;
   virtual void GetSystemInformation(
       const GetSystemInformationCallback& callback) OVERRIDE;
+  virtual scoped_ptr<std::string> GetHistograms() OVERRIDE;
 
  private:
   void ProcessSystemLogs(scoped_ptr<chromeos::SystemLogsResponse> sys_info);
 
   // Overridden from FeedbackService:
   virtual base::WeakPtr<FeedbackService> GetWeakPtr() OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(FeedbackServiceImpl);
 };
 
@@ skipping 18 matching lines @@
 void FeedbackServiceImpl::GetSystemInformation(
     const GetSystemInformationCallback& callback) {
   system_information_callback_ = callback;
 
   chromeos::ScrubbedSystemLogsFetcher* fetcher =
       new chromeos::ScrubbedSystemLogsFetcher();
   fetcher->Fetch(base::Bind(&FeedbackServiceImpl::ProcessSystemLogs,
                             AsWeakPtr()));
 }
 
+scoped_ptr<std::string> FeedbackServiceImpl::GetHistograms() {

[Alexei Svitkine (slow), 2013/11/02 00:05:26]

It's pretty weird as an API to return a scoped_ptr<std::string>, it's not
commonly done.

I suggest instead using an out param here (and in related calls), i.e.:

bool FeedbackServiceImpl::GetHistograms(std::string* histograms)

Then, you don't need to alloc the string object on the heap here.

[michaelpg, 2013/11/02 17:39:09]

Replaced scoped_ptr with out param.

+  scoped_ptr<std::string> json(new std::string);
+  base::StatisticsRecorder::WriteJSON(std::string(), json.get());
+  return json.Pass();
+}
+
 void FeedbackServiceImpl::ProcessSystemLogs(
     scoped_ptr<chromeos::SystemLogsResponse> sys_info_map) {
   SystemInformationList sys_info_list;
   if (!sys_info_map.get()) {
     system_information_callback_.Run(sys_info_list);
     return;
   }
 
   for (chromeos::SystemLogsResponse::iterator it = sys_info_map->begin();
        it != sys_info_map->end(); ++it)
     FeedbackService::PopulateSystemInfo(&sys_info_list, it->first, it->second);
 
   system_information_callback_.Run(sys_info_list);
 }
 
 base::WeakPtr<FeedbackService> FeedbackServiceImpl::GetWeakPtr() {
   return AsWeakPtr();
 }
 
 }  // namespace extensions