Define a few simple UMA metrics for the component updater.

components/component_updater/component_updater_service_unittest.cc

Index: components/component_updater/component_updater_service_unittest.cc
diff --git a/components/component_updater/component_updater_service_unittest.cc b/components/component_updater/component_updater_service_unittest.cc
index 15b62bb853b087008a9839e768f104ac969ce3d9..83d5874ed16a9d11fd286b2d315018fc27d8983a 100644
--- a/components/component_updater/component_updater_service_unittest.cc
+++ b/components/component_updater/component_updater_service_unittest.cc
@@ -15,6 +15,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/sequenced_worker_pool_owner.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/values.h"
@@ -215,6 +216,7 @@ TEST_F(ComponentUpdaterTest, RegisterComponent) {
     void OnUpdate(const std::vector<std::string>& ids,
                   const UpdateClient::CrxDataCallback& crx_data_callback,
                   const UpdateClient::CompletionCallback& completion_callback) {
+      completion_callback.Run(0);
       static int cnt = 0;
       ++cnt;
       if (cnt >= max_cnt_)
@@ -226,6 +228,8 @@ TEST_F(ComponentUpdaterTest, RegisterComponent) {
     base::Closure quit_closure_;
   };
 
+  base::HistogramTester ht;
+
   scoped_refptr<MockInstaller> installer(new MockInstaller());
   EXPECT_CALL(*installer, Uninstall()).WillOnce(Return(true));
 
@@ -260,8 +264,11 @@ TEST_F(ComponentUpdaterTest, RegisterComponent) {
   EXPECT_TRUE(component_updater().RegisterComponent(crx_component2));
 
   RunThreads();
-
   EXPECT_TRUE(component_updater().UnregisterComponent(id1));
+
+  ht.ExpectUniqueSample("ComponentUpdater.Calls", 1, 2);
+  ht.ExpectUniqueSample("ComponentUpdater.UpdateCompleteResult", 0, 2);
+  ht.ExpectTotalCount("ComponentUpdater.UpdateCompleteTime", 2);
 }
 
 // Tests that on-demand updates invoke UpdateClient::Install.
@@ -275,6 +282,7 @@ TEST_F(ComponentUpdaterTest, OnDemandUpdate) {
         const std::string& ids,
         const UpdateClient::CrxDataCallback& crx_data_callback,
         const UpdateClient::CompletionCallback& completion_callback) {
+      completion_callback.Run(0);
       static int cnt = 0;
       ++cnt;
       if (cnt >= max_cnt_)
@@ -286,6 +294,8 @@ TEST_F(ComponentUpdaterTest, OnDemandUpdate) {
     base::Closure quit_closure_;
   };
 
+  base::HistogramTester ht;
+
   auto config = configurator();
   config->SetInitialDelay(3600);
 
@@ -312,6 +322,10 @@ TEST_F(ComponentUpdaterTest, OnDemandUpdate) {
   EXPECT_TRUE(OnDemandTester::OnDemand(&cus, id));
 
   RunThreads();
+
+  ht.ExpectUniqueSample("ComponentUpdater.Calls", 0, 1);
+  ht.ExpectUniqueSample("ComponentUpdater.UpdateCompleteResult", 0, 1);
+  ht.ExpectTotalCount("ComponentUpdater.UpdateCompleteTime", 1);
 }
 
 // Tests that throttling an update invokes UpdateClient::Install.
@@ -325,6 +339,7 @@ TEST_F(ComponentUpdaterTest, MaybeThrottle) {
         const std::string& ids,
         const UpdateClient::CrxDataCallback& crx_data_callback,
         const UpdateClient::CompletionCallback& completion_callback) {
+      completion_callback.Run(0);
       static int cnt = 0;
       ++cnt;
       if (cnt >= max_cnt_)
@@ -336,6 +351,8 @@ TEST_F(ComponentUpdaterTest, MaybeThrottle) {
     base::Closure quit_closure_;
   };
 
+  base::HistogramTester ht;
+
   auto config = configurator();
   config->SetInitialDelay(3600);
 
@@ -359,6 +376,10 @@ TEST_F(ComponentUpdaterTest, MaybeThrottle) {
       base::Bind(&ComponentUpdaterTest::ReadyCallback));
 
   RunThreads();
+
+  ht.ExpectUniqueSample("ComponentUpdater.Calls", 0, 1);
+  ht.ExpectUniqueSample("ComponentUpdater.UpdateCompleteResult", 0, 1);
+  ht.ExpectTotalCount("ComponentUpdater.UpdateCompleteTime", 1);
 }
 
 }  // namespace component_updater