Ship Transferable Streams

Remove the feature flag for Transferable Streams and turn it on by
default.

Also remove the web test that I created to stop us shipping it by
accident, since now we are shipping it on purpose.

See the intent to ship thread at
https://groups.google.com/a/chromium.org/g/blink-dev/c/1LStSgBt6AM/m/sJaTciPKBwAJ
and the completed TAG review at
w3ctag/design-reviews#551.

BUG=894838

Change-Id: I56f8891bd1051202ef68bb4623ad8bec53045dff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2428509
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811606}

content/child/runtime_features.cc

@@ -370,7 +370,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
           {"RawClipboard", blink::features::kRawClipboard},
           {"ShadowDOMV0", blink::features::kWebComponentsV0},
           {"StorageAccessAPI", blink::features::kStorageAccessAPI},
-          {"TransferableStreams", blink::features::kTransferableStreams},
           {"TrustedDOMTypes", features::kTrustedDOMTypes},
           {"UserAgentClientHint", features::kUserAgentClientHint},
           {"WebAppManifestDisplayOverride",

testing/variations/fieldtrial_testing_config.json

@@ -6943,27 +6943,6 @@
             ]
         }
     ],
-    "TransferableStreams": [
-        {
-            "platforms": [
-                "android",
-                "android_weblayer",
-                "android_webview",
-                "chromeos",
-                "linux",
-                "mac",
-                "windows"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "enable_features": [
-                        "TransferableStreams"
-                    ]
-                }
-            ]
-        }
-    ],
     "TranslateCompactUI": [
         {
             "platforms": [

third_party/blink/common/features.cc

@@ -750,11 +750,6 @@ const base::Feature kReducedReferrerGranularity{
 const base::Feature kContentCaptureUserActivatedDelay = {
     "ContentCaptureUserActivatedDelay", base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Enable ReadableStream, WritableStream and TransformStream objects to be
-// transferred with postMessage().
-const base::Feature kTransferableStreams{"TransferableStreams",
-                                         base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Dispatches a fake fetch event to a service worker to check the offline
 // capability of the site before promoting installation.
 // See https://crbug.com/965802 for more details.

third_party/blink/public/common/features.h

@@ -303,8 +303,6 @@ BLINK_COMMON_EXPORT extern const base::Feature kReducedReferrerGranularity;
 BLINK_COMMON_EXPORT extern const base::Feature
     kContentCaptureUserActivatedDelay;
 
-BLINK_COMMON_EXPORT extern const base::Feature kTransferableStreams;
-
 BLINK_COMMON_EXPORT extern const base::Feature kCheckOfflineCapability;
 
 BLINK_COMMON_EXPORT extern const base::Feature

third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer_test.cc

@@ -55,7 +55,6 @@
 #include "third_party/blink/renderer/platform/file_metadata.h"
 #include "third_party/blink/renderer/platform/graphics/unaccelerated_static_bitmap_image.h"
 #include "third_party/blink/renderer/platform/heap/heap.h"
-#include "third_party/blink/renderer/platform/testing/runtime_enabled_features_test_helpers.h"
 #include "third_party/blink/renderer/platform/wtf/date_math.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImage.h"
@@ -1879,8 +1878,6 @@ TEST(V8ScriptValueSerializerTest, DecodeWithInefficientVersionEnvelope) {
 // Sanity check for transferring ReadableStreams. This is mostly tested via
 // web tests.
 TEST(V8ScriptValueSerializerTest, RoundTripReadableStream) {
-  ScopedTransferableStreamsForTest enable_transferable_streams(true);
-
   V8TestingScope scope;
   auto* isolate = scope.GetIsolate();
   auto* script_state = scope.GetScriptState();
@@ -1903,8 +1900,6 @@ TEST(V8ScriptValueSerializerTest, RoundTripReadableStream) {
 }
 
 TEST(V8ScriptValueSerializerTest, TransformStreamIntegerOverflow) {
-  ScopedTransferableStreamsForTest enable_transferable_streams(true);
-
   V8TestingScope scope;
   auto* isolate = scope.GetIsolate();
   auto* script_state = scope.GetScriptState();

third_party/blink/renderer/core/streams/readable_stream_test.cc

@@ -21,7 +21,6 @@
 #include "third_party/blink/renderer/platform/bindings/script_state.h"
 #include "third_party/blink/renderer/platform/bindings/string_resource.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
-#include "third_party/blink/renderer/platform/testing/runtime_enabled_features_test_helpers.h"
 #include "third_party/blink/renderer/platform/testing/unit_test_helpers.h"
 #include "v8/include/v8.h"
 
@@ -354,8 +353,6 @@ TEST_F(ReadableStreamTest, LockAndDisturb) {
 }
 
 TEST_F(ReadableStreamTest, Serialize) {
-  ScopedTransferableStreamsForTest enabled(true);
-
   V8TestingScope scope;
   auto* script_state = scope.GetScriptState();
   auto* isolate = scope.GetIsolate();

third_party/blink/renderer/core/streams/writable_stream_test.cc

@@ -14,7 +14,6 @@
 #include "third_party/blink/renderer/platform/bindings/script_state.h"
 #include "third_party/blink/renderer/platform/bindings/v8_binding.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
-#include "third_party/blink/renderer/platform/testing/runtime_enabled_features_test_helpers.h"
 #include "third_party/blink/renderer/platform/testing/unit_test_helpers.h"
 #include "v8/include/v8.h"
 
@@ -48,8 +47,6 @@ TEST(WritableStreamTest, GetWriter) {
 }
 
 TEST(WritableStreamTest, Serialize) {
-  ScopedTransferableStreamsForTest enable_transferable_streams(true);
-
   V8TestingScope scope;
   auto* script_state = scope.GetScriptState();
 

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1870,7 +1870,7 @@
     },
     {
       name: "TransferableStreams",
-      status: "experimental",
+      status: "stable",
       origin_trial_feature_name: "RTCInsertableStreams",
       implied_by: ["RTCInsertableStreams"],
     },

third_party/blink/web_tests/VirtualTestSuites

@@ -111,7 +111,6 @@
     "prefix": "stable",
     "bases": ["fast/css3-text/css3-text-decoration/stable",
               "fast/dom/Window",
-              "http/tests/streams/transferable/enabled",
               "http/tests/navigation",
               "http/tests/origin_trials/feature-policy-reporting",
               "http/tests/sendbeacon",