V8ValueConverter for the activity logger that does not invoke interceptors and

chrome/renderer/extensions/activity_log_value_converter.cc

+// Copyright (c) 2013 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 "base/values.h"
+#include "chrome/renderer/extensions/activity_log_value_converter.h"
+
+namespace extensions {
+
+ActivityLogValueConverter::ActivityLogValueConverter()
+    : v8_value_converter_(content::V8ValueConverter::create()) {
+}
+
+ActivityLogValueConverter::~ActivityLogValueConverter() {}
+
+base::Value* ActivityLogValueConverter::FromV8Value(
+    v8::Handle<v8::Value> value,
+    v8::Handle<v8::Context> context) const {
+
+  if (!value->IsObject())
+    return v8_value_converter_->FromV8Value(value, context);
+
+  // Handle JSObject.
+  // We cannot use value->Get(key/index) as there may be an accessor installed
+  // on the key/index. If that is the case, V8ValueConverter will execute the
+  // getter function which may interfere with the JS execution environment in
+  // the way unexpected by a developer. Moreover, executing getter functions may
+  // lead to recursive logging by ActivityLog when the getter accesses
+  // properties or issues calls on a JS object that happens to be a wrapper of a
+  // DOM object. V8 API does not allow to check if a property has a getter
+  // method installed. One way to do it is by using getOwnPropertyDescriptor
+  // method of the JS object; however, the function may be redefined and return
+  // bogus values. Apart from accessors, a JS object may have an interceptor
+  // installed which is not a problem as it can be tested with the
+  // HasNamedLookupInterceptor and HasIndexedLookupInterceptor V8 API calls.
+
+  v8::Handle<v8::String> name = v8::String::New("[");
+
+  if (value->IsFunction()) {
+    name =  v8::String::Concat(name, v8::String::New("Function"));
+    v8::Handle<v8::Value> fname =
+        v8::Handle<v8::Function>::Cast(value)->GetName();
+    if (fname->IsString() && v8::Handle<v8::String>::Cast(fname)->Length()) {
+      name = v8::String::Concat(name, v8::String::New(" "));
+      name = v8::String::Concat(name, v8::Handle<v8::String>::Cast(fname));
+      name = v8::String::Concat(name, v8::String::New("()"));
+    }
+  } else {
+    name = v8::String::Concat(name, value->ToObject()->GetConstructorName());
+  }
+
+  name = v8::String::Concat(name, v8::String::New("]"));
+  v8::String::Utf8Value utf8(name);
+  return new base::StringValue(std::string(*utf8, utf8.length()));
+}
+
+}  // namespace extensions
+