[Origin Trials] Install origin trial bindings on V8 context conditionally

third_party/WebKit/Source/core/workers/WorkerThread.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 15 matching lines @@
 
 #include "core/workers/WorkerThread.h"
 
 #include "bindings/core/v8/Microtask.h"
 #include "bindings/core/v8/ScriptSourceCode.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8IdleTaskRunner.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/inspector/InspectorTaskRunner.h"
 #include "core/inspector/WorkerThreadDebugger.h"
+#include "core/origin_trials/OriginTrialContext.h"
 #include "core/workers/WorkerBackingThread.h"
 #include "core/workers/WorkerClients.h"
 #include "core/workers/WorkerReportingProxy.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "platform/WaitableEvent.h"
 #include "platform/WebThreadSupportingGC.h"
 #include "platform/heap/SafePoint.h"
 #include "platform/heap/ThreadState.h"
 #include "platform/weborigin/KURL.h"
@@ skipping 292 matching lines @@
 
         // Optimize for memory usage instead of latency for the worker isolate.
         isolate()->IsolateInBackgroundNotification();
         m_workerGlobalScope = createWorkerGlobalScope(std::move(startupData));
         m_workerGlobalScope->scriptLoaded(sourceCode.length(), cachedMetaData.get() ? cachedMetaData->size() : 0);
 
         // Notify proxy that a new WorkerGlobalScope has been created and started.
         m_workerReportingProxy.workerGlobalScopeStarted(m_workerGlobalScope.get());
 
         WorkerOrWorkletScriptController* scriptController = m_workerGlobalScope->scriptController();
-        if (!scriptController->isExecutionForbidden())
+        if (!scriptController->isExecutionForbidden()) {
             scriptController->initializeContextIfNeeded();
+
+            // If Origin Trials have been registered before the V8 context was ready,

[haraken, 2016/05/27 00:01:42]

I'm just curious but how can we enable origin-trials attributes on workers?
Workers won't have <meta> tags... Is there any special syntax for HTTP headers?

[iclelland, 2016/05/27 03:19:43]

Yes, all resources can now be sent with an HTTP header "origin-trial", which
will also define any tokens to be used for that resource. This is the only way
right now to enable trials on service workers or shared workers.

Dedicated workers can use the HTTP header, and they also inherit any trials that
were enabled by their parent document.

+            // then inject them into the context now
+            ExecutionContext* executionContext = m_workerGlobalScope->getExecutionContext();
+            if (executionContext) {
+                OriginTrialContext* originTrialContext = OriginTrialContext::from(executionContext);
+                if (originTrialContext)
+                    originTrialContext->initializePendingTrials();
+            }
+        }
     }
 
     if (startMode == PauseWorkerGlobalScopeOnStart)
         startRunningDebuggerTasksOnPause();
 
     if (m_workerGlobalScope->scriptController()->isContextInitialized()) {
         m_workerReportingProxy.didInitializeWorkerContext();
         v8::HandleScope handleScope(isolate());
         Platform::current()->workerContextCreated(m_workerGlobalScope->scriptController()->context());
     }
@@ skipping 97 matching lines @@
 
 void WorkerThread::runDebuggerTaskDontWaitOnWorkerThread()
 {
     DCHECK(isCurrentThread());
     std::unique_ptr<CrossThreadClosure> task = m_inspectorTaskRunner->takeNextTask(InspectorTaskRunner::DontWaitForTask);
     if (task)
         (*task)();
 }
 
 } // namespace blink