Fix some leaks and failures under valgrind in JS extensions unit tests.

extensions/renderer/api_test_base.cc

 // Copyright 2014 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 "extensions/renderer/api_test_base.h"
 
 #include <vector>
 
 #include "base/run_loop.h"
 #include "extensions/common/extension_urls.h"
@@ skipping 89 matching lines @@
 }
 ApiTestBase::~ApiTestBase() {
 }
 
 void ApiTestBase::SetUp() {
   ModuleSystemTest::SetUp();
   InitializeEnvironment();
   RegisterModules();
 }
 
+void ApiTestBase::TearDown() {
+  env()->context()->DispatchOnUnloadEvent();
+  ModuleSystemTest::TearDown();
+}
+
 void ApiTestBase::RegisterModules() {
   v8_schema_registry_.reset(new V8SchemaRegistry);
   const std::vector<std::pair<std::string, int> > resources =
       Dispatcher::GetJsResources();
   for (std::vector<std::pair<std::string, int> >::const_iterator resource =
            resources.begin();
        resource != resources.end();
        ++resource) {
     if (resource->first != "test_environment_specific_bindings")
       env()->RegisterModule(resource->first, resource->second);
@@ skipping 92 matching lines @@
 }
 
 void ApiTestBase::RunPromisesAgain() {
   RunResolvedPromises();
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&ApiTestBase::RunPromisesAgain, base::Unretained(this)));
 }
 
 }  // namespace extensions