Retrieve client_id from GoogleUpdateSettings when its missing from Local State.

components/metrics/metrics_state_manager_unittest.cc

Index: components/metrics/metrics_state_manager_unittest.cc
diff --git a/components/metrics/metrics_state_manager_unittest.cc b/components/metrics/metrics_state_manager_unittest.cc
index 2f7d85be2aa6055e133944d5e22ecfb52634dc24..93c6842292d7c66e6885e1258b6a5366a88ab2f4 100644
--- a/components/metrics/metrics_state_manager_unittest.cc
+++ b/components/metrics/metrics_state_manager_unittest.cc
@@ -10,6 +10,7 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/prefs/testing_pref_service.h"
+#include "components/metrics/client_info.h"
 #include "components/metrics/metrics_pref_names.h"
 #include "components/metrics/metrics_switches.h"
 #include "components/variations/caching_permuted_entropy_provider.h"
@@ -28,6 +29,10 @@ class MetricsStateManagerTest : public testing::Test {
     return MetricsStateManager::Create(
         &prefs_,
         base::Bind(&MetricsStateManagerTest::is_metrics_reporting_enabled,
+                   base::Unretained(this)),
+        base::Bind(&MetricsStateManagerTest::MockStoreClientInfoBackup,
+                   base::Unretained(this)),
+        base::Bind(&MetricsStateManagerTest::LoadFakeClientInfoBackup,
                    base::Unretained(this))).Pass();
   }
 
@@ -44,8 +49,32 @@ class MetricsStateManagerTest : public testing::Test {
     return is_metrics_reporting_enabled_;
   }
 
+  // Stores the |client_info| in |stored_client_info_backup_| for verification
+  // by the tests later.
+  void MockStoreClientInfoBackup(const ClientInfo& client_info) {
+    stored_client_info_backup_.reset(new ClientInfo);
+    stored_client_info_backup_->client_id = client_info.client_id;
+    stored_client_info_backup_->installation_date =
+        client_info.installation_date;
+    stored_client_info_backup_->reporting_enabled_date =
+        client_info.reporting_enabled_date;
+  }
+
+  // Hands off |fake_client_info_backup_| if it was set.
+  scoped_ptr<ClientInfo> LoadFakeClientInfoBackup() {
+    return fake_client_info_backup_.Pass();
+  }
+
   bool is_metrics_reporting_enabled_;
 
+  // Last ClientInfo store via MockStoreClientInfoBackup by the
+  // MetricsStateManager.
+  scoped_ptr<ClientInfo> stored_client_info_backup_;
+
+  // If set, will be returned via LoadFakeClientInfoBackup if requested by the
+  // MetricsStateManager.
+  scoped_ptr<ClientInfo> fake_client_info_backup_;
+
   DISALLOW_COPY_AND_ASSIGN(MetricsStateManagerTest);
 };