Implement the mac policy provider based on the AsyncPolicyLoader.

chrome/browser/policy/configuration_policy_provider_test.cc

Index: chrome/browser/policy/configuration_policy_provider_test.cc
diff --git a/chrome/browser/policy/configuration_policy_provider_test.cc b/chrome/browser/policy/configuration_policy_provider_test.cc
index 3f1084fdfe554d949d7db075ca9bb4bfe792e692..74545413bb6ba417d62b17d5f7d6c0adb9ea9b82 100644
--- a/chrome/browser/policy/configuration_policy_provider_test.cc
+++ b/chrome/browser/policy/configuration_policy_provider_test.cc
@@ -16,6 +16,7 @@
 #include "policy/policy_constants.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
+using content::BrowserThread;
 using ::testing::Mock;
 using ::testing::_;
 
@@ -43,6 +44,16 @@ const PolicyDefinitionList kList = {
 
 }  // namespace test_policy_definitions
 
+PolicyTestBase::PolicyTestBase()
+    : ui_thread_(BrowserThread::UI, &loop_),
+      file_thread_(BrowserThread::FILE, &loop_) {}
+
+PolicyTestBase::~PolicyTestBase() {}
+
+void PolicyTestBase::TearDown() {
+  loop_.RunAllPending();
+}
+
 PolicyProviderTestHarness::PolicyProviderTestHarness(PolicyLevel level,
                                                      PolicyScope scope)
     : level_(level), scope_(scope) {}
@@ -62,7 +73,7 @@ ConfigurationPolicyProviderTest::ConfigurationPolicyProviderTest() {}
 ConfigurationPolicyProviderTest::~ConfigurationPolicyProviderTest() {}
 
 void ConfigurationPolicyProviderTest::SetUp() {
-  AsynchronousPolicyTestBase::SetUp();
+  PolicyTestBase::SetUp();
 
   test_harness_.reset((*GetParam())());
   test_harness_->SetUp();
@@ -81,7 +92,7 @@ void ConfigurationPolicyProviderTest::TearDown() {
   // Give providers the chance to clean up after themselves on the file thread.
   provider_.reset();
 
-  AsynchronousPolicyTestBase::TearDown();
+  PolicyTestBase::TearDown();
 }
 
 void ConfigurationPolicyProviderTest::CheckValue(