[DevTools] Copy objects from debugger context to inspected context properly.

third_party/WebKit/Source/platform/v8_inspector/V8ValueCopier.cpp

Index: third_party/WebKit/Source/platform/v8_inspector/V8ValueCopier.cpp
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8ValueCopier.cpp b/third_party/WebKit/Source/platform/v8_inspector/V8ValueCopier.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..3347abeba5929aa7c15fa3c05afc4c3072a8232c
--- /dev/null
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8ValueCopier.cpp
@@ -0,0 +1,90 @@
+// Copyright 2016 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.
+
+#include "platform/v8_inspector/V8ValueCopier.h"
+
+namespace v8_inspector {
+
+namespace {
+
+static int kMaxDepth = 20;
+static int kMaxCalls = 1000;
+
+class V8ValueCopier {
+public:
+    v8::MaybeLocal<v8::Value> copy(v8::Local<v8::Value> value, int depth)
+    {
+        if (++m_calls > kMaxCalls || depth > kMaxDepth)
+            return v8::MaybeLocal<v8::Value>();
+
+        if (value.IsEmpty())
+            return v8::MaybeLocal<v8::Value>();
+        if (value->IsNull() || value->IsUndefined() || value->IsBoolean() || value->IsString() || value->IsNumber())
+            return value;
+        if (!value->IsObject())
+            return v8::MaybeLocal<v8::Value>();
+        v8::Local<v8::Object> object = value.As<v8::Object>();
+        if (object->CreationContext() != m_from)
+            return value;
+
+        if (object->IsArray()) {
+            v8::Local<v8::Array> array = object.As<v8::Array>();
+            v8::Local<v8::Array> result = v8::Array::New(m_isolate, array->Length());
+            if (!result->SetPrototype(m_to, v8::Null(m_isolate)).FromMaybe(false))
+                return v8::MaybeLocal<v8::Value>();
+            for (size_t i = 0; i < array->Length(); ++i) {
+                v8::Local<v8::Value> item;
+                if (!array->Get(m_from, i).ToLocal(&item))
+                    return v8::MaybeLocal<v8::Value>();
+                v8::Local<v8::Value> copied;
+                if (!copy(item, depth + 1).ToLocal(&copied))
+                    return v8::MaybeLocal<v8::Value>();
+                if (!result->Set(m_to, i, copied).FromMaybe(false))
+                    return v8::MaybeLocal<v8::Value>();
+            }
+            return result;
+        }
+
+
+        v8::Local<v8::Object> result = v8::Object::New(m_isolate);
+        if (!result->SetPrototype(m_to, v8::Null(m_isolate)).FromMaybe(false))
+            return v8::MaybeLocal<v8::Value>();
+        v8::Local<v8::Array> properties;
+        if (!object->GetOwnPropertyNames(m_from).ToLocal(&properties))
+            return v8::MaybeLocal<v8::Value>();
+        for (size_t i = 0; i < properties->Length(); ++i) {
+            v8::Local<v8::Value> name;
+            if (!properties->Get(m_from, i).ToLocal(&name) || !name->IsString())
+                return v8::MaybeLocal<v8::Value>();
+            v8::Local<v8::Value> property;
+            if (!object->Get(m_from, name).ToLocal(&property))
+                return v8::MaybeLocal<v8::Value>();
+            v8::Local<v8::Value> copied;
+            if (!copy(property, depth + 1).ToLocal(&copied))
+                return v8::MaybeLocal<v8::Value>();
+            if (!result->Set(m_to, name, copied).FromMaybe(false))
+                return v8::MaybeLocal<v8::Value>();
+        }
+        return result;
+    }
+
+    v8::Isolate* m_isolate;
+    v8::Local<v8::Context> m_from;
+    v8::Local<v8::Context> m_to;
+    int m_calls;
+};
+
+} // namespace
+
+v8::MaybeLocal<v8::Value> copyValueFromDebuggerContext(v8::Isolate* isolate, v8::Local<v8::Context> debuggerContext, v8::Local<v8::Context> toContext, v8::Local<v8::Value> value)
+{
+    V8ValueCopier copier;
+    copier.m_isolate = isolate;
+    copier.m_from = debuggerContext;
+    copier.m_to = toContext;
+    copier.m_calls = 0;
+    return copier.copy(value, 0);
+}
+
+} // namespace v8_inspector