Begin to enable extension APIs in Extension Service Worker.

third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp

Index: third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp b/third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp
index 5d73eba912b751c4202c91332a6d521c214e076a..a69fb5533cac352d38c77e306df7623223c6ffd6 100644
--- a/third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/WorkerOrWorkletScriptController.cpp
@@ -31,6 +31,7 @@
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 
 #include "bindings/core/v8/ScriptCallStack.h"
+#include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/ScriptSourceCode.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8DedicatedWorkerGlobalScope.h"
@@ -50,6 +51,7 @@
 #include "core/workers/WorkerThread.h"
 #include "platform/heap/ThreadState.h"
 #include "public/platform/Platform.h"
+#include "wtf/Threading.h"
 #include <v8.h>
 
 namespace blink {
@@ -106,6 +108,24 @@ WorkerOrWorkletScriptController* WorkerOrWorkletScriptController::create(WorkerO
     return new WorkerOrWorkletScriptController(globalScope, isolate);
 }
 
+V8Extensions& WorkerOrWorkletScriptController::registeredExtensions()
+{
+    // Accessed from worker threads.
+    DEFINE_THREAD_SAFE_STATIC_LOCAL(V8Extensions, extensions, new V8Extensions);
+    return extensions;
+}
+
+void WorkerOrWorkletScriptController::registerExtensionIfNeeded(v8::Extension* extension)
+{
+    const V8Extensions& extensions = registeredExtensions();
+    for (size_t i = 0; i < extensions.size(); ++i) {
+        if (extensions[i] == extension)
+            return;
+    }
+    v8::RegisterExtension(extension);

[yhirano, 2016/04/22 02:28:11]

Naive question, is this function thread-safe?

[lazyboy, 2016/04/22 03:25:25]

Good question, It seems this would eventually call
RegisteredExtension::Register() in v8, which seems to build some kind of link
between |extension|.

I've got rid of this though after haraken@'s suggestion.

+    registeredExtensions().append(extension);
+}
+
 WorkerOrWorkletScriptController::WorkerOrWorkletScriptController(WorkerOrWorkletGlobalScope* globalScope, v8::Isolate* isolate)
     : m_globalScope(globalScope)
     , m_isolate(isolate)
@@ -165,8 +185,18 @@ bool WorkerOrWorkletScriptController::initializeContextIfNeeded()
     v8::Local<v8::ObjectTemplate> globalTemplate = globalInterfaceTemplate->InstanceTemplate();
     v8::Local<v8::Context> context;
     {
+        // Initialize V8 extensions before creating the context.
+        Vector<const char*> extensionNames;
+        if (m_globalScope->isServiceWorkerGlobalScope()) {

[haraken, 2016/04/21 07:50:44]

Slightly better:

  CHECK(m_globalScope->isServiceWorkerGlobalScope() ||
registeredExtensions().size() == 0);

[lazyboy, 2016/04/22 00:17:39]

Since the latest patch uses ScriptController::registeredExtensions(),
registeredExtensions().size can be > 0 for non service worker global scope.

+            const V8Extensions& extensions = registeredExtensions();
+            extensionNames.reserveInitialCapacity(extensions.size());
+            for (const auto* extension : extensions)
+                extensionNames.append(extension->name());
+        }
+        v8::ExtensionConfiguration extensionConfiguration(extensionNames.size(), extensionNames.data());
+
         V8PerIsolateData::UseCounterDisabledScope useCounterDisabled(V8PerIsolateData::from(m_isolate));
-        context = v8::Context::New(m_isolate, nullptr, globalTemplate);
+        context = v8::Context::New(m_isolate, &extensionConfiguration, globalTemplate);
     }
     if (context.IsEmpty())
         return false;