Initial implementation of bindings and basic classes for worklets.

third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 683 matching lines @@
     v8::Local<v8::Context> context = isolate->GetCallingContext();
     if (context.IsEmpty()) {
         // Unfortunately, when processing script from a plugin, we might not
         // have a calling context. In those cases, we fall back to the
         // entered context.
         context = isolate->GetEnteredContext();
     }
     return toLocalDOMWindow(toDOMWindow(context));
 }
 
+namespace {
+ExecutionContext* (*s_toExecutionContextForModules)(v8::Local<v8::Context>) = nullptr;
+}
+
 ExecutionContext* toExecutionContext(v8::Local<v8::Context> context)
 {
     if (context.IsEmpty())
         return 0;
     v8::Local<v8::Object> global = context->Global();
     v8::Local<v8::Object> windowWrapper = V8Window::findInstanceInPrototypeChain(global, context->GetIsolate());
     if (!windowWrapper.IsEmpty())
         return V8Window::toImpl(windowWrapper)->executionContext();
     v8::Local<v8::Object> workerWrapper = V8WorkerGlobalScope::findInstanceInPrototypeChain(global, context->GetIsolate());
     if (!workerWrapper.IsEmpty())
         return V8WorkerGlobalScope::toImpl(workerWrapper)->executionContext();
-    // FIXME: Is this line of code reachable?
-    return 0;
+    RELEASE_ASSERT(s_toExecutionContextForModules);

[haraken, 2016/01/12 00:38:49]

This is a performance-sensitive path, so let's use ASSERT not RELEASE_ASSERT.
Even if we don't have the ASSERT, the worst thing that can happen is just
(safely) crashing at the next line.

[ikilpatrick, 2016/01/12 04:11:24]

Done.

+    return (*s_toExecutionContextForModules)(context);
+}
+
+void registerToExecutionContextForModules(ExecutionContext* (*toExecutionContextForModules)(v8::Local<v8::Context>))
+{
+    s_toExecutionContextForModules = toExecutionContextForModules;
 }
 
 ExecutionContext* currentExecutionContext(v8::Isolate* isolate)
 {
     return toExecutionContext(isolate->GetCurrentContext());
 }
 
 ExecutionContext* callingExecutionContext(v8::Isolate* isolate)
 {
     v8::Local<v8::Context> context = isolate->GetCallingContext();
@@ skipping 43 matching lines @@
     result.setSmall(storage, length);
 }
 
 v8::Local<v8::Context> toV8Context(ExecutionContext* context, DOMWrapperWorld& world)
 {
     ASSERT(context);
     if (context->isDocument()) {
         if (LocalFrame* frame = toDocument(context)->frame())
             return toV8Context(frame, world);
     } else if (context->isWorkerGlobalScope()) {
-        if (WorkerOrWorkletScriptController* script = toWorkerGlobalScope(context)->script()) {
+        if (WorkerOrWorkletScriptController* script = toWorkerOrWorkletGlobalScope(context)->script()) {
             if (script->scriptState()->contextIsValid())
                 return script->scriptState()->context();
         }
     }
     return v8::Local<v8::Context>();
 }
 
 v8::Local<v8::Context> toV8Context(Frame* frame, DOMWrapperWorld& world)
 {
     if (!frame)
@@ skipping 229 matching lines @@
     v8::Local<v8::Value> data = info.Data();
     ASSERT(data->IsExternal());
     V8PerContextData* perContextData = V8PerContextData::from(info.Holder()->CreationContext());
     if (!perContextData)
         return;
     v8SetReturnValue(info, perContextData->constructorForType(WrapperTypeInfo::unwrap(data)));
     TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8Execution");
 }
 
 } // namespace blink