1 files changed, 97 insertions, 82 deletions

diff --git a/chromium/third_party/WebKit/Source/bindings/v8/ScriptState.h b/chromium/third_party/WebKit/Source/bindings/v8/ScriptState.h
index ac93b551167..81bc5840070 100644
--- a/chromium/third_party/WebKit/Source/bindings/v8/ScriptState.h
+++ b/chromium/third_party/WebKit/Source/bindings/v8/ScriptState.h
@@ -1,130 +1,145 @@
-/*
- * Copyright (C) 2008, 2009, 2011 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
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2014 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.
 
 #ifndef ScriptState_h
 #define ScriptState_h
 
 #include "bindings/v8/ScopedPersistent.h"
-#include "bindings/v8/V8Utilities.h"
+#include "bindings/v8/V8PerContextData.h"
+#include "wtf/RefCounted.h"
 #include <v8.h>
-#include "wtf/Noncopyable.h"
 
 namespace WebCore {
 
-class DOMWindow;
+class LocalDOMWindow;
 class DOMWrapperWorld;
-class Frame;
 class ExecutionContext;
-class WorkerGlobalScope;
+class LocalFrame;
+class ScriptValue;
 
-class ScriptState {
+// ScriptState is created when v8::Context is created.
+// ScriptState is destroyed when v8::Context is garbage-collected and
+// all V8 proxy objects that have references to the ScriptState are destructed.
+class ScriptState : public RefCounted<ScriptState> {
     WTF_MAKE_NONCOPYABLE(ScriptState);
 public:
-    bool hadException() { return !m_exception.isEmpty(); }
-    void setException(v8::Local<v8::Value> exception)
+    class Scope {
+    public:
+        // You need to make sure that scriptState->context() is not empty before creating a Scope.
+        explicit Scope(ScriptState* scriptState)
+            : m_handleScope(scriptState->isolate())
+            , m_context(scriptState->context())
+        {
+            ASSERT(!m_context.IsEmpty());
+            m_context->Enter();
+        }
+
+        ~Scope()
+        {
+            m_context->Exit();
+        }
+
+    private:
+        v8::HandleScope m_handleScope;
+        v8::Handle<v8::Context> m_context;
+    };
+
+    static PassRefPtr<ScriptState> create(v8::Handle<v8::Context>, PassRefPtr<DOMWrapperWorld>);
+    virtual ~ScriptState();
+
+    static ScriptState* current(v8::Isolate* isolate)
     {
-        m_exception.set(m_isolate, exception);
+        return from(isolate->GetCurrentContext());
     }
-    v8::Local<v8::Value> exception() { return m_exception.newLocal(m_isolate); }
-    void clearException() { m_exception.clear(); }
 
-    v8::Local<v8::Context> context() const
+    static ScriptState* from(v8::Handle<v8::Context> context)
     {
-        return m_context.newLocal(m_isolate);
+        ASSERT(!context.IsEmpty());
+        ScriptState* scriptState = static_cast<ScriptState*>(context->GetAlignedPointerFromEmbedderData(v8ContextPerContextDataIndex));
+        // ScriptState::from() must not be called for a context that does not have
+        // valid embedder data in the embedder field.
+        RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(scriptState);
+        RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(scriptState->context() == context);
+        return scriptState;
     }
 
-    v8::Isolate* isolate()
-    {
-        return m_isolate;
-    }
+    static ScriptState* forMainWorld(LocalFrame*);
+
+    v8::Isolate* isolate() const { return m_isolate; }
+    DOMWrapperWorld& world() const { return *m_world; }
+    LocalDOMWindow* domWindow() const;
+    virtual ExecutionContext* executionContext() const;
+    virtual void setExecutionContext(ExecutionContext*);
+
+    // This can return an empty handle if the v8::Context is gone.
+    v8::Handle<v8::Context> context() const { return m_context.newLocal(m_isolate); }
+    bool contextIsEmpty() const { return m_context.isEmpty(); }
+    void clearContext() { return m_context.clear(); }
+
+    V8PerContextData* perContextData() const { return m_perContextData.get(); }
+    void disposePerContextData() { m_perContextData = nullptr; }
 
-    DOMWindow* domWindow() const;
-    ExecutionContext* executionContext() const;
     bool evalEnabled() const;
     void setEvalEnabled(bool);
-
-    static ScriptState* forContext(v8::Handle<v8::Context>);
-    static ScriptState* current();
+    ScriptValue getFromGlobalObject(const char* name);
 
 protected:
-    ScriptState()
-        : m_isolate(v8::Isolate::GetCurrent())
-    {
-    }
-
-    ~ScriptState();
+    ScriptState(v8::Handle<v8::Context>, PassRefPtr<DOMWrapperWorld>);
 
 private:
-    friend ScriptState* mainWorldScriptState(Frame*);
-    explicit ScriptState(v8::Handle<v8::Context>);
+    v8::Isolate* m_isolate;
+    // This persistent handle is weak.
+    ScopedPersistent<v8::Context> m_context;
 
-    static void setWeakCallback(const v8::WeakCallbackData<v8::Context, ScriptState>&);
+    // This RefPtr doesn't cause a cycle because all persistent handles that DOMWrapperWorld holds are weak.
+    RefPtr<DOMWrapperWorld> m_world;
 
-    ScopedPersistent<v8::Value> m_exception;
-    ScopedPersistent<v8::Context> m_context;
-    v8::Isolate* m_isolate;
+    // This OwnPtr causes a cycle:
+    // V8PerContextData --(Persistent)--> v8::Context --(RefPtr)--> ScriptState --(OwnPtr)--> V8PerContextData
+    // So you must explicitly clear the OwnPtr by calling disposePerContextData()
+    // once you no longer need V8PerContextData. Otherwise, the v8::Context will leak.
+    OwnPtr<V8PerContextData> m_perContextData;
 };
 
-class EmptyScriptState : public ScriptState {
+class ScriptStateForTesting : public ScriptState {
 public:
-    EmptyScriptState() : ScriptState() { }
-    ~EmptyScriptState() { }
+    static PassRefPtr<ScriptStateForTesting> create(v8::Handle<v8::Context>, PassRefPtr<DOMWrapperWorld>);
+
+    virtual ExecutionContext* executionContext() const OVERRIDE;
+    virtual void setExecutionContext(ExecutionContext*) OVERRIDE;
+
+private:
+    ScriptStateForTesting(v8::Handle<v8::Context>, PassRefPtr<DOMWrapperWorld>);
+
+    ExecutionContext* m_executionContext;
 };
 
-class ScriptStateProtectedPtr {
-    WTF_MAKE_NONCOPYABLE(ScriptStateProtectedPtr);
+// ScriptStateProtectingContext keeps the context associated with the ScriptState alive.
+// You need to call clear() once you no longer need the context. Otherwise, the context will leak.
+class ScriptStateProtectingContext {
+    WTF_MAKE_NONCOPYABLE(ScriptStateProtectingContext);
 public:
-    ScriptStateProtectedPtr()
-        : m_scriptState(0)
+    ScriptStateProtectingContext(ScriptState* scriptState)
+        : m_scriptState(scriptState)
     {
+        if (m_scriptState)
+            m_context.set(m_scriptState->isolate(), m_scriptState->context());
     }
 
-    ScriptStateProtectedPtr(ScriptState* scriptState)
-        : m_scriptState(scriptState)
+    ScriptState* operator->() const { return m_scriptState.get(); }
+    ScriptState* get() const { return m_scriptState.get(); }
+    void clear()
     {
-        v8::HandleScope handleScope(scriptState->isolate());
-        // Keep the context from being GC'ed. ScriptState is guaranteed to be live while the context is live.
-        m_context.set(scriptState->isolate(), scriptState->context());
+        m_scriptState = nullptr;
+        m_context.clear();
     }
 
-    ScriptState* get() const { return m_scriptState; }
-
 private:
-    ScriptState* m_scriptState;
+    RefPtr<ScriptState> m_scriptState;
     ScopedPersistent<v8::Context> m_context;
 };
 
-ScriptState* mainWorldScriptState(Frame*);
-
-ScriptState* scriptStateFromWorkerGlobalScope(WorkerGlobalScope*);
-
 }
 
 #endif // ScriptState_h