Transitively keep track of an isolated world's children scripts and worlds.

third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h

Index: third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h
index aeadf0611815e4309a02ae1ff14b3d0e32f98888..500557034989ca5fd6a91d5cec4df1d95a04007a 100644
--- a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h
+++ b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h
@@ -35,6 +35,7 @@
 #include "core/CoreExport.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "wtf/MainThread.h"
+#include "wtf/OwnPtr.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
@@ -60,6 +61,33 @@ template<typename T> class DOMObjectHolder;
 // This class represent a collection of DOM wrappers for a specific world.
 class CORE_EXPORT DOMWrapperWorld : public RefCounted<DOMWrapperWorld> {
 public:
+    class OriginWorldScope {
+        WTF_MAKE_NONCOPYABLE(OriginWorldScope);
+
+    public:
+        explicit OriginWorldScope(PassRefPtr<DOMWrapperWorld> originWorld)
+            : m_hasPushed(false)
+        {
+            ASSERT(isMainThread());
+            if (originWorld) {
+                DOMWrapperWorld::originWorldStack().append(originWorld);
+                m_hasPushed = true;
+            }
+        }
+
+        ~OriginWorldScope()
+        {
+            ASSERT(isMainThread());
+            // "Pop" the origin world to avoid tainting the entire document.
+            if (m_hasPushed) {
+                DOMWrapperWorld::originWorldStack().removeLast();
+            }
+        }
+
+    private:
+        bool m_hasPushed;
+    };
+
     static PassRefPtr<DOMWrapperWorld> create(v8::Isolate*, int worldId = -1, int extensionGroup = -1);
 
     static const int mainWorldExtensionGroup = 0;
@@ -115,9 +143,23 @@ public:
     bool isPrivateScriptIsolatedWorld() const { return m_worldId == PrivateScriptIsolatedWorldId; }
     bool isWorkerWorld() const { return m_worldId == WorkerWorldId; }
     bool isIsolatedWorld() const { return MainWorldId < m_worldId  && m_worldId < IsolatedWorldIdLimit; }
+    DOMWrapperWorld* originWorld()
+    {
+        if (isIsolatedWorld())
+            return this;
+        if (isMainThread() && !originWorldStack().isEmpty())
+            return originWorldStack().last().get();
+        return nullptr;
+    };
+    bool isOfIsolatedWorldOrigin() const
+    {
+        ASSERT(isMainThread());
+        return isIsolatedWorld() ? true : originWorldStack().isEmpty() ? false : originWorldStack().last().get()->isIsolatedWorld();
+    };
 
     int worldId() const { return m_worldId; }
     int extensionGroup() const { return m_extensionGroup; }
+
     DOMDataStore& domDataStore() const { return *m_domDataStore; }
 
     static void setWorldOfInitializingWindow(DOMWrapperWorld* world)
@@ -133,6 +175,8 @@ public:
 private:
     DOMWrapperWorld(v8::Isolate*, int worldId, int extensionGroup);
 
+    static Vector<RefPtr<DOMWrapperWorld>>& originWorldStack();
+
     static void weakCallbackForDOMObjectHolder(const v8::WeakCallbackInfo<DOMObjectHolderBase>&);
     void registerDOMObjectHolderInternal(PassOwnPtr<DOMObjectHolderBase>);
     void unregisterDOMObjectHolder(DOMObjectHolderBase*);