Fix build.

test/unittests/test-isolate.cc

 // Copyright 2014 the V8 project 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 "test/unittests/test-isolate.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using testing::NotNull;
 
 namespace v8 {
 namespace internal {
 
 IsolateTest::IsolateTest() : isolate_(v8::Isolate::New()) {
-  ASSERT_THAT(isolate_, NotNull());
+  EXPECT_THAT(isolate_, NotNull());
   isolate_->Enter();
 }
 
 
 IsolateTest::~IsolateTest() {
-  ASSERT_THAT(isolate_, NotNull());
+  EXPECT_THAT(isolate_, NotNull());
   isolate_->Exit();
   isolate_->Dispose();
   isolate_ = NULL;
 }
 
 
 v8::Isolate* IsolateTest::isolate() const {
   EXPECT_THAT(isolate_, NotNull());
   return isolate_;
 }
 
 
 TEST_F(IsolateTest, GetCurrent) {
   EXPECT_THAT(v8::Isolate::GetCurrent(), NotNull());
   EXPECT_EQ(v8::Isolate::GetCurrent(), isolate());
 }
 
 }  // namespace internal
 }  // namespace v8