Merge histograms from providers into StatisticsRecorder for display.

chrome/browser/metrics/subprocess_metrics_provider.cc

 // Copyright 2016 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/metrics/subprocess_metrics_provider.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 12 matching lines @@
 namespace {
 
 // This is used by tests that don't have an easy way to access the global
 // instance of this class.
 SubprocessMetricsProvider* g_subprocess_metrics_provider_for_testing;
 
 }  // namespace
 
 SubprocessMetricsProvider::SubprocessMetricsProvider()
     : scoped_observer_(this), weak_ptr_factory_(this) {
+  base::StatisticsRecorder::RegisterHistogramProvider(
+      weak_ptr_factory_.GetWeakPtr());
   content::BrowserChildProcessObserver::Add(this);
   registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CREATED,
                  content::NotificationService::AllBrowserContextsAndSources());
   g_subprocess_metrics_provider_for_testing = this;
 }
 
 SubprocessMetricsProvider::~SubprocessMetricsProvider() {
   // Safe even if this object has never been added as an observer.
   content::BrowserChildProcessObserver::Remove(this);
   g_subprocess_metrics_provider_for_testing = nullptr;
@@ skipping 172 matching lines @@
     return nullptr;
 
   std::unique_ptr<base::SharedPersistentMemoryAllocator> allocator =
       host->TakeMetricsAllocator();
   if (!allocator)
     return nullptr;
 
   return base::MakeUnique<base::PersistentHistogramAllocator>(
       std::move(allocator));
 }