[v8][wasm] Implement the origin trial flag for WebAssembly threads

The flag is passed to V8 via a callback which has already been
implemented in V8 in https://crrev.com/c/1163621.

Bug: 868844
Change-Id: Ic10c6330ba23a37c5dedd1073a0ea55c6cd86f7c
Reviewed-on: https://chromium-review.googlesource.com/1167187Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Jason Chase <chasej@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584685}

third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/wasm-threads-origin-trial.js

+// Copyright 2018 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.
+
+// Build a WebAssembly module which uses thread-features.
+function createBuilderWithThreads() {
+  const builder = new WasmModuleBuilder();
+  const shared = true;
+  builder.addMemory(2, 10, false, shared);
+  builder.addFunction('main', kSig_i_ii)
+      .addBody([
+        kExprGetLocal, 0, kExprGetLocal, 1, kAtomicPrefix, kExprI32AtomicAdd, 2,
+        0
+      ])
+      .exportFunc();
+  return builder;
+}
+
+// Starts the function provided by blobURL on a worker and checks that the data
+// the worker sends with postMessage is 'true'.
+function testModuleCompilationOnWorker(blobURL) {
+  let resolve;
+  // Create a promise which fulfills when the worker finishes.
+  let promise = new Promise(function(res, rej) {
+    resolve = res;
+  });
+
+  let worker = new Worker(blobURL);
+  worker.addEventListener('message', e => resolve(e.data));
+
+  // Send the module bytes to the worker, because the worker does not have
+  // access to the WasmModuleBuilder.
+  worker.postMessage(createBuilderWithThreads().toBuffer());
+
+  return promise.then(result => assert_true(result));
+}
+
+// Test that WebAssembly threads are disabled and a WebAssembly module which
+// uses shared memory and atomics cannot be compiled.
+function testWasmThreadsDisabled() {
+  // If WebAssembly threads are enabled even without origin trial token, then we
+  // do not run this test.
+  if (window.internals.runtimeFlags.webAssemblyThreadsEnabled)
+    return;
+
+  try {
+    // Compiling the WebAssembly bytes should throw a CompileError.
+    createBuilderWithThreads().toModule();
+    assert_unreachable();
+  } catch (e) {
+    assert_true(e instanceof WebAssembly.CompileError);
+  }
+}
+
+// Test that WebAssembly threads are disabled and a WebAssembly module which
+// uses shared memory and atomics cannot be compiled on a worker.
+function testWasmThreadsDisabledOnWorker() {
+  // If WebAssembly threads are enabled even without origin trial token, then
+  // we do not run this test.
+  if (window.internals.runtimeFlags.webAssemblyThreadsEnabled) {
+    return Promise.resolve();
+  }
+
+  const blobURL = URL.createObjectURL(new Blob(
+      [
+        '(',
+        function() {
+          self.addEventListener('message', data => {
+            try {
+              // Compiling the WebAssembly bytes should throw a CompileError.
+              new WebAssembly.Module(data.data);
+              self.postMessage(false);
+            } catch (e) {
+              self.postMessage(e instanceof WebAssembly.CompileError);
+            }
+          });
+        }.toString(),
+        ')()'
+      ],
+      {type: 'application/javascript'}));
+
+  return testModuleCompilationOnWorker(blobURL);
+}
+
+// Test that WebAssembly threads are enabled and a WebAssembly module which
+// uses shared memory and atomics can be compiled.
+function testWasmThreadsEnabled() {
+  const module = createBuilderWithThreads().toModule();
+  assert_true(module !== undefined);
+  assert_true(module instanceof WebAssembly.Module);
+}
+
+// Test that WebAssembly threads are enabled and a WebAssembly module which
+// uses shared memory and atomics can be compiled on a worker.
+function testWasmThreadsEnabledOnWorker() {
+  let blobURL = URL.createObjectURL(new Blob(
+      [
+        '(',
+        function() {
+          self.addEventListener('message', data => {
+            try {
+              const module = new WebAssembly.Module(data.data);
+              self.postMessage(module !== undefined);
+            } catch (e) {
+              console.log(e);
+              self.postMessage(false);
+            }
+          });
+        }.toString(),
+        ')()'
+      ],
+      {type: 'application/javascript'}));
+
+  return testModuleCompilationOnWorker(blobURL);
+}

third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/wasm-threads-origin-trial-disabled.html

+<!DOCTYPE html>
+<meta charset="utf-8">
+
+<script src="../../../../resources/testharness.js"></script>
+<script src="../../../../resources/testharnessreport.js"></script>
+
+<script src="../../wasm/resources/wasm-constants.js"></script>
+<script src="../../wasm/resources/wasm-module-builder.js"></script>
+<script src="resources/wasm-threads-origin-trial.js"></script>
+<script>
+test(testWasmThreadsDisabled,
+     "Test that WebAssembly threads are disabled without origin trial token");
+promise_test(testWasmThreadsDisabledOnWorker,
+     "Test that WebAssembly threads are disabled in worker without origin trial token");
+</script>

third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/wasm-threads-origin-trial-enabled.html

+<!DOCTYPE html>
+<meta charset="utf-8">
+<!-- Generate this token with the command:
+generate_token.py http://127.0.0.1:8000 WebAssemblyThreads --expire-timestamp=2000000000
+-->
+
+<meta http-equiv="origin-trial" content="AvA8hsoHU+5qiE3oR2wNRZKcI7MOkHl4Vdu3IX8IKv90k4tpNFIaC3KblOaOh9ND63YD/539iVGJ930KCYwotgoAAABaeyJvcmlnaW4iOiAiaHR0cDovLzEyNy4wLjAuMTo4MDAwIiwgImZlYXR1cmUiOiAiV2ViQXNzZW1ibHlUaHJlYWRzIiwgImV4cGlyeSI6IDIwMDAwMDAwMDB9" />
+
+<script src="../../../../resources/testharness.js"></script>
+<script src="../../../../resources/testharnessreport.js"></script>
+
+<script src="../../wasm/resources/wasm-constants.js"></script>
+<script src="../../wasm/resources/wasm-module-builder.js"></script>
+<script src="resources/wasm-threads-origin-trial.js"></script>
+<script>
+test(testWasmThreadsEnabled,
+     "Test that WebAssembly threads are enabled with origin trial token");
+promise_test(testWasmThreadsEnabledOnWorker,
+     "Test that WebAssembly threads are enabled in worker with origin trial token");
+</script>

third_party/blink/renderer/bindings/core/v8/v8_initializer.cc

@@ -58,6 +58,7 @@
 #include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/inspector/console_message.h"
 #include "third_party/blink/renderer/core/inspector/main_thread_debugger.h"
+#include "third_party/blink/renderer/core/origin_trials/origin_trials.h"
 #include "third_party/blink/renderer/core/page/page.h"
 #include "third_party/blink/renderer/core/script/modulator.h"
 #include "third_party/blink/renderer/core/workers/worker_global_scope.h"
@@ -505,6 +506,14 @@ static bool WasmCodeGenerationCheckCallbackInMainThread(
   return false;
 }
 
+static bool WasmThreadsEnabledCallback(v8::Local<v8::Context> context) {
+  ExecutionContext* execution_context = ToExecutionContext(context);
+  if (!execution_context)
+    return false;
+
+  return OriginTrials::WebAssemblyThreadsEnabled(execution_context);
+}
+
 v8::Local<v8::Value> NewRangeException(v8::Isolate* isolate,
                                        const char* message) {
   return v8::Exception::RangeError(
@@ -634,6 +643,7 @@ static void InitializeV8Common(v8::Isolate* isolate) {
   isolate->SetUseCounterCallback(&UseCounterCallback);
   isolate->SetWasmModuleCallback(WasmModuleOverride);
   isolate->SetWasmInstanceCallback(WasmInstanceOverride);
+  isolate->SetWasmThreadsEnabledCallback(WasmThreadsEnabledCallback);
   if (RuntimeEnabledFeatures::ModuleScriptsDynamicImportEnabled()) {
     isolate->SetHostImportModuleDynamicallyCallback(
         HostImportModuleDynamically);

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1254,6 +1254,11 @@
       name: "WebAssemblyStreaming",
       status: "experimental",
     },
+    {
+      name: "WebAssemblyThreads",
+      origin_trial_feature_name: "WebAssemblyThreads",
+      status: "experimental",
+    },
     {
       name: "WebAuth",
       status: "experimental",