Add an extensions keep-alive client.

extensions/renderer/api_test_base.cc

Index: extensions/renderer/api_test_base.cc
diff --git a/extensions/renderer/api_test_base.cc b/extensions/renderer/api_test_base.cc
index 7e3dd7ba8079aab7f1fe4a215aa42ee97fa381dc..8242d4ffb9cd62c8e50c896050e6917ebfcfd6a5 100644
--- a/extensions/renderer/api_test_base.cc
+++ b/extensions/renderer/api_test_base.cc
@@ -101,6 +101,52 @@ ApiTestBase::ApiTestBase() {
 ApiTestBase::~ApiTestBase() {
 }
 
+class KeepAliveCounter::Instance : public mojo::InterfaceImpl<KeepAlive> {
+ public:
+  Instance(KeepAliveCounter* counter);
+  ~Instance() override;
+
+ private:
+  KeepAliveCounter* counter_;
+
+  DISALLOW_COPY_AND_ASSIGN(Instance);
+};
+
+KeepAliveCounter::KeepAliveCounter() : keep_alives_(0), keep_alive_ends_(0) {
+}
+
+void KeepAliveCounter::CreateKeepAlive(
+    mojo::InterfaceRequest<KeepAlive> request) {
+  keep_alives_++;
+  mojo::BindToRequest(new Instance(this), &request);
+}
+
+void KeepAliveCounter::WaitUntilKeepAlivesFinish() {
+  base::RunLoop run_loop;
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(&KeepAliveCounter::PollKeepAlives,
+                            base::Unretained(this), run_loop.QuitClosure()));
+  run_loop.Run();
+}
+
+void KeepAliveCounter::PollKeepAlives(const base::Closure& quit_closure) {
+  if (keep_alives_ == keep_alive_ends_) {
+    quit_closure.Run();
+    return;
+  }
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(&KeepAliveCounter::PollKeepAlives,
+                            base::Unretained(this), quit_closure));
+}
+
+KeepAliveCounter::Instance::Instance(KeepAliveCounter* counter)
+    : counter_(counter) {
+}
+
+KeepAliveCounter::Instance::~Instance() {
+  counter_->keep_alive_ends_++;
+}
+
 void ApiTestBase::SetUp() {
   ModuleSystemTest::SetUp();
   InitializeEnvironment();
@@ -163,6 +209,9 @@ void ApiTestBase::RegisterModules() {
       ->AddBuiltinModule(env()->isolate(),
                          "content/public/renderer/service_provider",
                          service_provider.ToV8());
+  service_provider_->AddService(
+      base::Bind(&KeepAliveCounter::CreateKeepAlive,
+                 base::Unretained(&keep_alive_counter_)));
 }
 
 void ApiTestBase::InitializeEnvironment() {
@@ -197,6 +246,7 @@ void ApiTestBase::RunTest(const std::string& file_name,
       FROM_HERE,
       base::Bind(&ApiTestBase::RunPromisesAgain, base::Unretained(this)));
   run_loop.Run();
+  keep_alive_counter_.WaitUntilKeepAlivesFinish();
 }
 
 void ApiTestBase::RunTestInner(const std::string& test_name,