bindings: Use V8 MaybeLocal<> APIs in Dictionary class

Source/bindings/core/v8/Dictionary.cpp

Index: Source/bindings/core/v8/Dictionary.cpp
diff --git a/Source/bindings/core/v8/Dictionary.cpp b/Source/bindings/core/v8/Dictionary.cpp
index 91b09a48d1f3e5ddc70a0b17a746f658336fead6..1efca2be8f06e9a7371606689a8da4f13fb47e63 100644
--- a/Source/bindings/core/v8/Dictionary.cpp
+++ b/Source/bindings/core/v8/Dictionary.cpp
@@ -46,6 +46,15 @@
 
 namespace blink {
 
+#define TO_OBJECT_WITH_CHECK(context, value, object)                     \
+{                                                                        \
+    v8::MaybeLocal<v8::Object> maybeObject = value->ToObject(m_context); \
+    if (maybeObject.IsEmpty())                                           \
+        return false;                                                    \
+    if (!maybeObject.ToLocal(&object))                                   \
+        return false;                                                    \
+}
+
 static ExceptionState& emptyExceptionState()
 {
     AtomicallyInitializedStaticReference(WTF::ThreadSpecific<NonThrowableExceptionState>, exceptionState, new ThreadSpecific<NonThrowableExceptionState>);
@@ -65,6 +74,7 @@ Dictionary::Dictionary(const v8::Handle<v8::Value>& options, v8::Isolate* isolat
 {
     ASSERT(m_isolate);
     ASSERT(m_exceptionState);
+    subscribeScriptStateDisposal();
 #if ENABLE(ASSERT)
     m_exceptionState->onStackObjectChecker().add(this);
 #endif
@@ -72,6 +82,7 @@ Dictionary::Dictionary(const v8::Handle<v8::Value>& options, v8::Isolate* isolat
 
 Dictionary::~Dictionary()
 {
+    unsubscribeScriptStateDisposal();
 #if ENABLE(ASSERT)
     if (m_exceptionState)
         m_exceptionState->onStackObjectChecker().remove(this);
@@ -80,8 +91,10 @@ Dictionary::~Dictionary()
 
 Dictionary& Dictionary::operator=(const Dictionary& optionsObject)
 {
+    unsubscribeScriptStateDisposal();
     m_options = optionsObject.m_options;
     m_isolate = optionsObject.m_isolate;
+    subscribeScriptStateDisposal();
 #if ENABLE(ASSERT)
     if (m_exceptionState)
         m_exceptionState->onStackObjectChecker().remove(this);
@@ -115,14 +128,14 @@ bool Dictionary::hasProperty(const String& key) const
 {
     if (isUndefinedOrNull())
         return false;
-    v8::Local<v8::Object> options = m_options->ToObject(m_isolate);
-    ASSERT(!options.IsEmpty());
+    v8::Local<v8::Object> object;
+    TO_OBJECT_WITH_CHECK(m_context, m_options, object);
 
     ASSERT(m_isolate);
     ASSERT(m_isolate == v8::Isolate::GetCurrent());
     ASSERT(m_exceptionState);
     v8::Handle<v8::String> v8Key = v8String(m_isolate, key);
-    if (!options->Has(v8Key))
+    if (v8Key.IsEmpty() || !object->Has(v8Key))
         return false;
 
     return true;
@@ -132,19 +145,17 @@ bool Dictionary::getKey(const String& key, v8::Local<v8::Value>& value) const
 {
     if (isUndefinedOrNull())
         return false;
-    v8::Local<v8::Object> options = m_options->ToObject(m_isolate);
-    ASSERT(!options.IsEmpty());
+    v8::Local<v8::Object> object;
+    TO_OBJECT_WITH_CHECK(m_context, m_options, object);
 
     ASSERT(m_isolate);
     ASSERT(m_isolate == v8::Isolate::GetCurrent());
     ASSERT(m_exceptionState);
     v8::Handle<v8::String> v8Key = v8String(m_isolate, key);
-    if (!options->Has(v8Key))
-        return false;
-    value = options->Get(v8Key);
-    if (value.IsEmpty())
+    if (v8Key.IsEmpty() || !object->Has(v8Key))
         return false;
-    return true;
+    value = object->Get(v8Key);
+    return !value.IsEmpty();
 }
 
 bool Dictionary::get(const String& key, v8::Local<v8::Value>& value) const
@@ -171,11 +182,11 @@ bool Dictionary::set(const String& key, const v8::Handle<v8::Value>& value)
 {
     if (isUndefinedOrNull())
         return false;
-    v8::Local<v8::Object> options = m_options->ToObject(m_isolate);
-    ASSERT(!options.IsEmpty());
+    v8::Local<v8::Object> object;
+    TO_OBJECT_WITH_CHECK(m_context, m_options, object);
     ASSERT(m_exceptionState);
 
-    return options->Set(v8String(m_isolate, key), value);
+    return object->Set(v8String(m_isolate, key), value);
 }
 
 bool Dictionary::set(const String& key, const String& value)
@@ -216,19 +227,24 @@ bool Dictionary::getOwnPropertiesAsStringHashMap(HashMap<String, String>& hashMa
     if (!isObject())
         return false;
 
-    v8::Handle<v8::Object> options = m_options->ToObject(m_isolate);
-    if (options.IsEmpty())
-        return false;
+    v8::Local<v8::Object> object;
+    TO_OBJECT_WITH_CHECK(m_context, m_options, object);
 
-    v8::Local<v8::Array> properties = options->GetOwnPropertyNames();
+    v8::Local<v8::Array> properties = object->GetOwnPropertyNames();
     if (properties.IsEmpty())
         return true;
     for (uint32_t i = 0; i < properties->Length(); ++i) {
-        v8::Local<v8::String> key = properties->Get(i)->ToString(m_isolate);
-        if (!options->Has(key))
+        v8::Local<v8::Value> property = properties->Get(i);
+        if (property.IsEmpty())
+            continue;
+        v8::MaybeLocal<v8::String> maybeKey = properties->Get(i)->ToString(m_context);
+        v8::Local<v8::String> key;
+        if (!maybeKey.ToLocal(&key) || !object->Has(key))
             continue;
 
-        v8::Local<v8::Value> value = options->Get(key);
+        v8::Local<v8::Value> value = object->Get(key);
+        if (value.IsEmpty())
+            continue;
         TOSTRING_DEFAULT(V8StringResource<>, stringKey, key, false);
         TOSTRING_DEFAULT(V8StringResource<>, stringValue, value, false);
         if (!static_cast<const String&>(stringKey).isEmpty())
@@ -243,16 +259,19 @@ bool Dictionary::getPropertyNames(Vector<String>& names) const
     if (!isObject())
         return false;
 
-    v8::Handle<v8::Object> options = m_options->ToObject(m_isolate);
-    if (options.IsEmpty())
-        return false;
+    v8::Local<v8::Object> object;
+    TO_OBJECT_WITH_CHECK(m_context, m_options, object);
 
-    v8::Local<v8::Array> properties = options->GetPropertyNames();
+    v8::Local<v8::Array> properties = object->GetPropertyNames();
     if (properties.IsEmpty())
         return true;
     for (uint32_t i = 0; i < properties->Length(); ++i) {
-        v8::Local<v8::String> key = properties->Get(i)->ToString(m_isolate);
-        if (!options->Has(key))
+        v8::Local<v8::Value> property = properties->Get(i);
+        if (property.IsEmpty())
+            continue;
+        v8::MaybeLocal<v8::String> maybeKey = properties->Get(i)->ToString(m_context);
+        v8::Local<v8::String> key;
+        if (!maybeKey.ToLocal(&key) || !object->Has(key))
             continue;
         TOSTRING_DEFAULT(V8StringResource<>, stringKey, key, false);
         names.append(stringKey);
@@ -285,4 +304,27 @@ void Dictionary::ConversionContext::throwTypeError(const String& detail)
     exceptionState().throwTypeError(detail);
 }
 
+void Dictionary::willDisposeScriptState(ScriptState*)
+{
+    m_context.Clear();
+}
+
+void Dictionary::subscribeScriptStateDisposal()
+{
+    if (m_isolate) {
+        ScriptState* scriptState = ScriptState::current(m_isolate);
+        scriptState->addObserver(this);
+        m_context = scriptState->context();
+        ASSERT(!m_context.IsEmpty());
+    }
+}
+
+void Dictionary::unsubscribeScriptStateDisposal()
+{
+    if (m_isolate) {
+        ScriptState* scriptState = ScriptState::current(m_isolate);
+        scriptState->removeObserver(this);
+    }
+}
+
 } // namespace blink