| // Copyright (c) 2012 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/field_trial_synchronizer.h" |
| |
| #include "base/bind.h" |
| #include "base/logging.h" |
| #include "base/task/post_task.h" |
| #include "base/threading/thread.h" |
| #include "chrome/common/renderer_configuration.mojom.h" |
| #include "components/metrics/persistent_system_profile.h" |
| #include "content/public/browser/browser_task_traits.h" |
| #include "content/public/browser/browser_thread.h" |
| #include "content/public/browser/render_process_host.h" |
| |
| using content::BrowserThread; |
| |
| FieldTrialSynchronizer::FieldTrialSynchronizer() { |
| bool success = base::FieldTrialList::AddObserver(this); |
| // Ensure the observer was actually registered. |
| DCHECK(success); |
| } |
| |
| void FieldTrialSynchronizer::NotifyAllRenderers( |
| const std::string& field_trial_name, |
| const std::string& group_name) { |
| // To iterate over RenderProcessHosts, or to send messages to the hosts, we |
| // need to be on the UI thread. |
| DCHECK_CURRENTLY_ON(BrowserThread::UI); |
| |
| // Note this in the persistent profile as it will take a while for a new |
| // "complete" profile to be genereated. |
| metrics::GlobalPersistentSystemProfile::GetInstance()->AddFieldTrial( |
| field_trial_name, group_name); |
| |
| for (content::RenderProcessHost::iterator it( |
| content::RenderProcessHost::AllHostsIterator()); |
| !it.IsAtEnd(); it.Advance()) { |
| auto* host = it.GetCurrentValue(); |
| IPC::ChannelProxy* channel = host->GetChannel(); |
| // channel might be null in tests. |
| if (host->IsInitializedAndNotDead() && channel) { |
| chrome::mojom::RendererConfigurationAssociatedPtr renderer_configuration; |
| channel->GetRemoteAssociatedInterface(&renderer_configuration); |
| renderer_configuration->SetFieldTrialGroup(field_trial_name, group_name); |
| } |
| } |
| } |
| |
| void FieldTrialSynchronizer::OnFieldTrialGroupFinalized( |
| const std::string& field_trial_name, |
| const std::string& group_name) { |
| // The FieldTrialSynchronizer may have been created before any BrowserThread |
| // is created, so we don't need to synchronize with child processes in which |
| // case there are no child processes to notify yet. |
| if (!content::BrowserThread::IsThreadInitialized(BrowserThread::UI)) |
| return; |
| |
| base::PostTaskWithTraits( |
| FROM_HERE, {BrowserThread::UI}, |
| base::BindOnce(&FieldTrialSynchronizer::NotifyAllRenderers, this, |
| field_trial_name, group_name)); |
| } |
| |
| FieldTrialSynchronizer::~FieldTrialSynchronizer() { |
| base::FieldTrialList::RemoveObserver(this); |
| } |