Add message loop to v8's unittests

chrome/test/base/v8_unit_test.h

Index: chrome/test/base/v8_unit_test.h
diff --git a/chrome/test/base/v8_unit_test.h b/chrome/test/base/v8_unit_test.h
index 830da54beb1e5ef69070a49aae95fb6bce7e3ce8..2184973937f93d3fcdd5bd6d97b94ee0d0380d6e 100644
--- a/chrome/test/base/v8_unit_test.h
+++ b/chrome/test/base/v8_unit_test.h
@@ -13,6 +13,10 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "v8/include/v8.h"
 
+namespace base {
+class MessageLoop;
+}  // namespace base
+
 // A superclass for unit tests that involve running JavaScript.  This class
 // sets up V8 context and has methods that make it easy to execute scripts in
 // this context as well as call functions in the context.
@@ -82,6 +86,8 @@ class V8UnitTest : public testing::Test {
 
   // User added libraries.
   std::vector<base::FilePath> user_libraries_;
+
+  std::unique_ptr<base::MessageLoop> loop_;
 };
 
 #endif  // CHROME_TEST_BASE_V8_UNIT_TEST_H_