Gate `Sec-Fetch-Dest` on an additional feature flag.

We're aiming to ship most of Fetch Metadata before we've resolved
`Sec-Fetch-Dest` completely. This patch adds another feature flag
and RuntimeEnabledFeature to allow that.

Bug: 843478
Change-Id: I392e20b0bb5a5ab117a720e5d3800258fd3e6e9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1554662Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Auto-Submit: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#649840}

chrome/browser/ui/views/bookmarks/bookmark_bar_view_browsertest.cc

@@ -50,7 +50,10 @@ class BookmarkBarNavigationTest : public InProcessBrowserTest {
       : https_test_server_(net::EmbeddedTestServer::TYPE_HTTPS) {}
 
   void SetUp() override {
-    scoped_feature_list_.InitAndEnableFeature(network::features::kSecMetadata);
+    scoped_feature_list_.InitWithFeatures(
+        {network::features::kFetchMetadata,
+         network::features::kFetchMetadataDestination},
+        {});
     InProcessBrowserTest::SetUp();
   }
 

content/browser/frame_host/navigation_request.cc

@@ -139,8 +139,15 @@ bool IsSecureFrame(FrameTreeNode* frame) {
   return true;
 }
 
-bool IsSecMetadataEnabled() {
-  return base::FeatureList::IsEnabled(network::features::kSecMetadata) ||
+bool IsFetchMetadataEnabled() {
+  return base::FeatureList::IsEnabled(network::features::kFetchMetadata) ||
+         base::CommandLine::ForCurrentProcess()->HasSwitch(
+             switches::kEnableExperimentalWebPlatformFeatures);
+}
+
+bool IsFetchMetadataDestinationEnabled() {
+  return base::FeatureList::IsEnabled(
+             network::features::kFetchMetadataDestination) ||
          base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kEnableExperimentalWebPlatformFeatures);
 }
@@ -207,7 +214,7 @@ void AddAdditionalRequestHeaders(net::HttpRequestHeaders* headers,
 
   // TODO(mkwst): Extract this logic out somewhere that can be shared between
   // Blink and //content.
-  if (IsSecMetadataEnabled() && IsOriginSecure(url)) {
+  if (IsFetchMetadataEnabled() && IsOriginSecure(url)) {
     std::string site_value = "cross-site";
     std::string user_value = has_user_gesture ? "?1" : std::string();
 
@@ -251,7 +258,10 @@ void AddAdditionalRequestHeaders(net::HttpRequestHeaders* headers,
         destination = "nested-document";
         mode = "nested-navigate";
     }
-    headers->SetHeaderIfMissing("Sec-Fetch-Dest", destination.c_str());
+
+    if (IsFetchMetadataDestinationEnabled()) {
+      headers->SetHeaderIfMissing("Sec-Fetch-Dest", destination.c_str());
+    }
     headers->SetHeaderIfMissing("Sec-Fetch-Mode", mode.c_str());
     headers->SetHeaderIfMissing("Sec-Fetch-Site", site_value.c_str());
     if (!user_value.empty())

content/browser/frame_host/sec_fetch_browsertest.cc

@@ -37,7 +37,10 @@ class SecFetchBrowserTest : public ContentBrowserTest {
     https_test_server_.SetSSLConfig(net::EmbeddedTestServer::CERT_OK);
     ASSERT_TRUE(https_test_server_.Start());
 
-    feature_list_.InitAndEnableFeature(network::features::kSecMetadata);
+    feature_list_.InitWithFeatures(
+        {network::features::kFetchMetadata,
+         network::features::kFetchMetadataDestination},
+        {});
   }
 
   WebContents* web_contents() { return shell()->web_contents(); }

content/browser/worker_host/worker_script_fetch_initiator.cc

@@ -214,9 +214,11 @@ void WorkerScriptFetchInitiator::AddAdditionalRequestHeaders(
   }
 
   // Set Fetch metadata headers if necessary.
-  if ((base::FeatureList::IsEnabled(network::features::kSecMetadata) ||
-       base::CommandLine::ForCurrentProcess()->HasSwitch(
-           switches::kEnableExperimentalWebPlatformFeatures)) &&
+  bool experimental_features_enabled =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableExperimentalWebPlatformFeatures);
+  if ((base::FeatureList::IsEnabled(network::features::kFetchMetadata) ||
+       experimental_features_enabled) &&
       IsOriginSecure(resource_request->url)) {
     // The worker's origin can be different from the constructor's origin, for
     // example, when the worker created from the extension.
@@ -227,13 +229,18 @@ void WorkerScriptFetchInitiator::AddAdditionalRequestHeaders(
             url::Origin::Create(resource_request->url))) {
       site_value = "same-origin";
     }
-    resource_request->headers.SetHeaderIfMissing("Sec-Fetch-Dest",
-                                                 "sharedworker");
     resource_request->headers.SetHeaderIfMissing("Sec-Fetch-Site",
                                                  site_value.c_str());
     resource_request->headers.SetHeaderIfMissing("Sec-Fetch-Mode",
                                                  "same-origin");
     // We don't set `Sec-Fetch-User` for subresource requests.
+
+    if (base::FeatureList::IsEnabled(
+            network::features::kFetchMetadataDestination) ||
+        experimental_features_enabled) {
+      resource_request->headers.SetHeaderIfMissing("Sec-Fetch-Dest",
+                                                   "sharedworker");
+    }
   }
 }
 

content/child/runtime_features.cc

@@ -201,8 +201,12 @@ void SetIndividualRuntimeFeatures(
 
   // TODO(yashard): Remove |enable_experimental_web_platform_features| flag
   // since the feature should have been enabled when it is set to experimental
-  WebRuntimeFeatures::EnableSecMetadata(
-      base::FeatureList::IsEnabled(network::features::kSecMetadata) ||
+  WebRuntimeFeatures::EnableFetchMetadata(
+      base::FeatureList::IsEnabled(network::features::kFetchMetadata) ||
+      enable_experimental_web_platform_features);
+  WebRuntimeFeatures::EnableFetchMetadataDestination(
+      base::FeatureList::IsEnabled(
+          network::features::kFetchMetadataDestination) ||
       enable_experimental_web_platform_features);
 
   WebRuntimeFeatures::EnableUserActivationPostMessageTransfer(

services/network/public/cpp/features.cc

@@ -60,8 +60,14 @@ const base::Feature kEnforceRequestInitiatorLockForCorb{
     "EnforceRequestInitiatorLockForCorb", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Implementation of https://mikewest.github.io/sec-metadata/
-const base::Feature kSecMetadata{"SecMetadata",
-                                 base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kFetchMetadata{"FetchMetadata",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
+// The `Sec-Fetch-Dest` header is split out from the main "FetchMetadata"
+// feature so we can ship the broader feature without this specifific bit
+// while we continue discussion.
+const base::Feature kFetchMetadataDestination{
+    "FetchMetadataDestination", base::FEATURE_DISABLED_BY_DEFAULT};
 
 bool ShouldEnableOutOfBlinkCors() {
   // OOR-CORS requires NetworkService.

services/network/public/cpp/features.h

@@ -28,7 +28,9 @@ extern const base::Feature kDelayRequestsOnMultiplexedConnections;
 COMPONENT_EXPORT(NETWORK_CPP)
 extern const base::Feature kEnforceRequestInitiatorLockForCorb;
 COMPONENT_EXPORT(NETWORK_CPP)
-extern const base::Feature kSecMetadata;
+extern const base::Feature kFetchMetadata;
+COMPONENT_EXPORT(NETWORK_CPP)
+extern const base::Feature kFetchMetadataDestination;
 
 COMPONENT_EXPORT(NETWORK_CPP) bool ShouldEnableOutOfBlinkCors();
 

third_party/blink/public/platform/web_runtime_features.h

@@ -171,7 +171,8 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableScriptedSpeechRecognition(bool);
   BLINK_PLATFORM_EXPORT static void EnableScriptedSpeechSynthesis(bool);
   BLINK_PLATFORM_EXPORT static void EnableScrollAnchorSerialization(bool);
-  BLINK_PLATFORM_EXPORT static void EnableSecMetadata(bool);
+  BLINK_PLATFORM_EXPORT static void EnableFetchMetadata(bool);
+  BLINK_PLATFORM_EXPORT static void EnableFetchMetadataDestination(bool);
   BLINK_PLATFORM_EXPORT static void EnableSharedArrayBuffer(bool);
   BLINK_PLATFORM_EXPORT static void EnableSharedWorker(bool);
   BLINK_PLATFORM_EXPORT static void EnableTextFragmentAnchor(bool);

third_party/blink/renderer/core/loader/base_fetch_context.cc

@@ -144,7 +144,7 @@ void BaseFetchContext::AddAdditionalRequestHeaders(ResourceRequest& request) {
 
   scoped_refptr<SecurityOrigin> url_origin =
       SecurityOrigin::Create(request.Url());
-  if (blink::RuntimeEnabledFeatures::SecMetadataEnabled() &&
+  if (blink::RuntimeEnabledFeatures::FetchMetadataEnabled() &&
       url_origin->IsPotentiallyTrustworthy()) {
     const char* destination_value =
         GetDestinationFromContext(request.GetRequestContext());
@@ -154,7 +154,7 @@ void BaseFetchContext::AddAdditionalRequestHeaders(ResourceRequest& request) {
     if (strlen(destination_value) == 0)
       destination_value = "empty";
 
-    // We'll handle adding the header to navigations outside of Blink.
+    // We'll handle adding these headers to navigations outside of Blink.
     if (strncmp(destination_value, "document", 8) != 0 &&
         request.GetRequestContext() != mojom::RequestContextType::INTERNAL) {
       const char* site_value = "cross-site";
@@ -173,7 +173,10 @@ void BaseFetchContext::AddAdditionalRequestHeaders(ResourceRequest& request) {
         }
       }
 
-      request.SetHttpHeaderField("Sec-Fetch-Dest", destination_value);
+      if (blink::RuntimeEnabledFeatures::FetchMetadataDestinationEnabled()) {
+        request.SetHttpHeaderField("Sec-Fetch-Dest", destination_value);
+      }
+
       request.SetHttpHeaderField(
           "Sec-Fetch-Mode",
           FetchRequestModeToString(request.GetFetchRequestMode()));

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -519,8 +519,12 @@ void WebRuntimeFeatures::EnableScrollAnchorSerialization(bool enable) {
   RuntimeEnabledFeatures::SetScrollAnchorSerializationEnabled(enable);
 }
 
-void WebRuntimeFeatures::EnableSecMetadata(bool enable) {
-  RuntimeEnabledFeatures::SetSecMetadataEnabled(enable);
+void WebRuntimeFeatures::EnableFetchMetadata(bool enable) {
+  RuntimeEnabledFeatures::SetFetchMetadataEnabled(enable);
+}
+
+void WebRuntimeFeatures::EnableFetchMetadataDestination(bool enable) {
+  RuntimeEnabledFeatures::SetFetchMetadataDestinationEnabled(enable);
 }
 
 void WebRuntimeFeatures::EnableTimerThrottlingForBackgroundTabs(bool enable) {

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -549,6 +549,14 @@
     {
       name: "FeaturePolicyVibrateFeature"
     },
+    {
+      name: "FetchMetadata",
+      status: "experimental"
+    },
+    {
+      name: "FetchMetadataDestination",
+      status: "experimental"
+    },
     {
       name: "FileSystem",
       status: "stable",
@@ -1268,10 +1276,6 @@
       name: "ScrollTopLeftInterop",
       status: "stable",
     },
-    {
-      name: "SecMetadata",
-      status: "experimental"
-    },
     {
       name: "SendBeaconThrowForBlobWithNonSimpleType",
       status: "stable",