From 57147d1b8d1352e8f49d6086b9957869d0d1e75a Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Wed, 31 May 2023 17:06:25 +0200
Subject: [PATCH] fix: `navigator.connection` not working as intended (#38491)

* fix: navigator.connection not working as intended

* chore: make network quality methods private
---
 shell/browser/browser_process_impl.cc        | 21 +++++++++++++++++
 shell/browser/browser_process_impl.h         | 10 ++++++++
 shell/browser/electron_browser_main_parts.cc |  2 ++
 spec/chromium-spec.ts                        | 24 ++++++++++++++++++++
 4 files changed, 57 insertions(+)

diff --git a/shell/browser/browser_process_impl.cc b/shell/browser/browser_process_impl.cc
index 29beeab14f14..d9c6a89a25ba 100644
--- a/shell/browser/browser_process_impl.cc
+++ b/shell/browser/browser_process_impl.cc
@@ -25,6 +25,8 @@
 #include "components/proxy_config/proxy_config_dictionary.h"
 #include "components/proxy_config/proxy_config_pref_names.h"
 #include "content/public/browser/child_process_security_policy.h"
+#include "content/public/browser/network_quality_observer_factory.h"
+#include "content/public/browser/network_service_instance.h"
 #include "content/public/common/content_switches.h"
 #include "electron/fuses.h"
 #include "extensions/common/constants.h"
@@ -125,6 +127,10 @@ void BrowserProcessImpl::PreCreateThreads() {
     SystemNetworkContextManager::CreateInstance(local_state_.get());
 }
 
+void BrowserProcessImpl::PreMainMessageLoopRun() {
+  CreateNetworkQualityObserver();
+}
+
 void BrowserProcessImpl::PostMainMessageLoopRun() {
   if (local_state_)
     local_state_->CommitPendingWrite();
@@ -333,3 +339,18 @@ void BrowserProcessImpl::SetGeolocationManager(
     std::unique_ptr<device::GeolocationManager> geolocation_manager) {
   geolocation_manager_ = std::move(geolocation_manager);
 }
+
+network::NetworkQualityTracker* BrowserProcessImpl::GetNetworkQualityTracker() {
+  if (!network_quality_tracker_) {
+    network_quality_tracker_ = std::make_unique<network::NetworkQualityTracker>(
+        base::BindRepeating(&content::GetNetworkService));
+  }
+  return network_quality_tracker_.get();
+}
+
+void BrowserProcessImpl::CreateNetworkQualityObserver() {
+  DCHECK(!network_quality_observer_);
+  network_quality_observer_ =
+      content::CreateNetworkQualityObserver(GetNetworkQualityTracker());
+  DCHECK(network_quality_observer_);
+}
diff --git a/shell/browser/browser_process_impl.h b/shell/browser/browser_process_impl.h
index 8109f5f6542c..a70822f6d6c3 100644
--- a/shell/browser/browser_process_impl.h
+++ b/shell/browser/browser_process_impl.h
@@ -19,6 +19,7 @@
 #include "components/prefs/pref_service.h"
 #include "components/prefs/value_map_pref_store.h"
 #include "printing/buildflags/buildflags.h"
+#include "services/network/public/cpp/network_quality_tracker.h"
 #include "services/network/public/cpp/shared_url_loader_factory.h"
 #include "shell/browser/net/system_network_context_manager.h"
 
@@ -45,6 +46,7 @@ class BrowserProcessImpl : public BrowserProcess {
   BuildState* GetBuildState() override;
   void PostEarlyInitialization();
   void PreCreateThreads();
+  void PreMainMessageLoopRun();
   void PostDestroyThreads() {}
   void PostMainMessageLoopRun();
 
@@ -113,6 +115,9 @@ class BrowserProcessImpl : public BrowserProcess {
       std::unique_ptr<device::GeolocationManager> geolocation_manager) override;
 
  private:
+  void CreateNetworkQualityObserver();
+  network::NetworkQualityTracker* GetNetworkQualityTracker();
+
 #if BUILDFLAG(ENABLE_PRINTING)
   std::unique_ptr<printing::PrintJobManager> print_job_manager_;
 #endif
@@ -121,6 +126,11 @@ class BrowserProcessImpl : public BrowserProcess {
   std::string locale_;
   std::string system_locale_;
   embedder_support::OriginTrialsSettingsStorage origin_trials_settings_storage_;
+
+  std::unique_ptr<network::NetworkQualityTracker> network_quality_tracker_;
+  std::unique_ptr<
+      network::NetworkQualityTracker::RTTAndThroughputEstimatesObserver>
+      network_quality_observer_;
 };
 
 #endif  // ELECTRON_SHELL_BROWSER_BROWSER_PROCESS_IMPL_H_
diff --git a/shell/browser/electron_browser_main_parts.cc b/shell/browser/electron_browser_main_parts.cc
index 97df7fe7f0d5..ae820127614a 100644
--- a/shell/browser/electron_browser_main_parts.cc
+++ b/shell/browser/electron_browser_main_parts.cc
@@ -537,6 +537,8 @@ int ElectronBrowserMainParts::PreMainMessageLoopRun() {
   // Notify observers that main thread message loop was initialized.
   Browser::Get()->PreMainMessageLoopRun();
 
+  fake_browser_process_->PreMainMessageLoopRun();
+
   return GetExitCode();
 }
 
diff --git a/spec/chromium-spec.ts b/spec/chromium-spec.ts
index 88f5e9238fd7..ceffda8549ce 100644
--- a/spec/chromium-spec.ts
+++ b/spec/chromium-spec.ts
@@ -1970,6 +1970,30 @@ describe('chromium features', () => {
     });
   });
 
+  // https://developer.mozilla.org/en-US/docs/Web/API/NetworkInformation
+  describe('navigator.connection', () => {
+    it('returns the correct value', async () => {
+      const w = new BrowserWindow({ show: false });
+
+      w.webContents.session.enableNetworkEmulation({
+        latency: 500,
+        downloadThroughput: 6400,
+        uploadThroughput: 6400
+      });
+
+      await w.loadURL(`file://${fixturesPath}/pages/blank.html`);
+      const rtt = await w.webContents.executeJavaScript('navigator.connection.rtt');
+      expect(rtt).to.be.a('number');
+
+      const downlink = await w.webContents.executeJavaScript('navigator.connection.downlink');
+      expect(downlink).to.be.a('number');
+
+      const effectiveTypes = ['slow-2g', '2g', '3g', '4g'];
+      const effectiveType = await w.webContents.executeJavaScript('navigator.connection.effectiveType');
+      expect(effectiveTypes).to.include(effectiveType);
+    });
+  });
+
   describe('navigator.userAgentData', () => {
     // These tests are done on an http server because navigator.userAgentData
     // requires a secure context.