Expose disable_idle_sockets_close_on_memory_pressure as feature

Adds a chrome Feature to disable closing idle sockets on memory
pressure. This only applies to Profile NetworkContexts.

Bug: 1150526
Test: new browser test
Change-Id: I0e4f18d8faa4f365bdd7dc404003e147ca47aa8c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2547723Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Pavol Marko <pmarko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829161}

chrome/browser/net/profile_network_context_service.cc

@@ -70,6 +70,7 @@
 #include "chrome/browser/chromeos/policy/policy_cert_service_factory.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/policy/profile_policy_connector.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/constants/chromeos_switches.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
@@ -828,6 +829,13 @@ void ProfileNetworkContextService::ConfigureNetworkContextParamsInternal(
         GetAdditionalCertificates(policy_cert_service,
                                   GetPartitionPath(relative_partition_path));
   }
+  // Disable idle sockets close on memory pressure if configured by finch or
+  // about://flags.
+  if (base::FeatureList::IsEnabled(
+          chromeos::features::kDisableIdleSocketsCloseOnMemoryPressure)) {
+    network_context_params->disable_idle_sockets_close_on_memory_pressure =
+        true;
+  }
 #endif
 
   // Should be initialized with existing per-profile CORS access lists.

chrome/browser/net/profile_network_context_service_browsertest.cc

@@ -68,6 +68,10 @@
 #include "services/network/public/mojom/url_loader_factory.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_CHROMEOS)
+#include "chromeos/constants/chromeos_features.h"
+#endif
+
 // Most tests for this class are in NetworkContextConfigurationBrowserTest.
 class ProfileNetworkContextServiceBrowsertest : public InProcessBrowserTest {
  public:
@@ -651,3 +655,58 @@ INSTANTIATE_TEST_SUITE_P(
     ProfileNetworkContextServiceCertVerifierBuiltinFeaturePolicyTestWithService,
     ::testing::Bool());
 #endif  // BUILDFLAG(BUILTIN_CERT_VERIFIER_FEATURE_SUPPORTED)
+
+#if defined(OS_CHROMEOS)
+class ProfileNetworkContextServiceMemoryPressureFeatureBrowsertest
+    : public ProfileNetworkContextServiceBrowsertest,
+      public ::testing::WithParamInterface<base::Optional<bool>> {
+ public:
+  ProfileNetworkContextServiceMemoryPressureFeatureBrowsertest() = default;
+  ~ProfileNetworkContextServiceMemoryPressureFeatureBrowsertest() override =
+      default;
+
+  void SetUp() override {
+    if (GetParam().has_value()) {
+      if (GetParam().value()) {
+        scoped_feature_list_.InitWithFeatures(
+            {chromeos::features::kDisableIdleSocketsCloseOnMemoryPressure}, {});
+      } else {
+        scoped_feature_list_.InitWithFeatures(
+            {}, {chromeos::features::kDisableIdleSocketsCloseOnMemoryPressure});
+      }
+    }
+    ProfileNetworkContextServiceBrowsertest::SetUp();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+};
+
+// If the feature is enabled (GetParam()==true),
+// NetworkContextParams.disable_idle_sockets_close_on_memory_pressure is
+// expected to be true.
+// If the feature is not set or disabled (GetParam()==false or nullopt),
+// NetworkContextParams.disable_idle_sockets_close_on_memory_pressure is
+// expected to be false
+IN_PROC_BROWSER_TEST_P(
+    ProfileNetworkContextServiceMemoryPressureFeatureBrowsertest,
+    FeaturePropagates) {
+  ProfileNetworkContextService* profile_network_context_service =
+      ProfileNetworkContextServiceFactory::GetForContext(browser()->profile());
+  base::FilePath empty_relative_partition_path;
+  network::mojom::NetworkContextParams network_context_params;
+  network::mojom::CertVerifierCreationParams cert_verifier_creation_params;
+  profile_network_context_service->ConfigureNetworkContextParams(
+      /*in_memory=*/false, empty_relative_partition_path,
+      &network_context_params, &cert_verifier_creation_params);
+  EXPECT_EQ(
+      GetParam().value_or(false),
+      network_context_params.disable_idle_sockets_close_on_memory_pressure);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    All,
+    ProfileNetworkContextServiceMemoryPressureFeatureBrowsertest,
+    /*disable_idle_sockets_close_on_memory_pressure=*/
+    ::testing::Values(base::nullopt, true, false));
+#endif  // defined(OS_CHROMEOS)

chromeos/constants/chromeos_features.cc

@@ -207,6 +207,15 @@ const base::Feature kCrostiniEnableDlc{"CrostiniEnableDlc",
 const base::Feature kCryptAuthV2DeviceActivityStatus{
     "CryptAuthV2DeviceActivityStatus", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Disable idle sockets closing on memory pressure for NetworkContexts that
+// belong to Profiles. It only applies to Profiles because the goal is to
+// improve perceived performance of web browsing within the Chrome OS user
+// session by avoiding re-estabshing TLS connections that require client
+// certificates.
+const base::Feature kDisableIdleSocketsCloseOnMemoryPressure{
+    "disable_idle_sockets_close_on_memory_pressure",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables or disables the CryptAuth v2 DeviceSync flow. Regardless of this
 // flag, v1 DeviceSync will continue to operate until it is disabled via the
 // feature flag kDisableCryptAuthV1DeviceSync.

chromeos/constants/chromeos_features.h

@@ -108,6 +108,8 @@ extern const base::Feature kDisableCryptAuthV1DeviceSync;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kCryptAuthV2DeviceActivityStatus;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
+extern const base::Feature kDisableIdleSocketsCloseOnMemoryPressure;
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kCrostiniWebUIUpgrader;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kCryptAuthV2DeviceSync;