Retrieve client_id from GoogleUpdateSettings when its missing from Local State.

chrome/browser/metrics/metrics_services_manager.cc

Index: chrome/browser/metrics/metrics_services_manager.cc
diff --git a/chrome/browser/metrics/metrics_services_manager.cc b/chrome/browser/metrics/metrics_services_manager.cc
index 8278913da7da438199e2c1b3f363649bc54148d3..effee1857671eca86035613975b4093fadf1e51f 100644
--- a/chrome/browser/metrics/metrics_services_manager.cc
+++ b/chrome/browser/metrics/metrics_services_manager.cc
@@ -4,12 +4,17 @@
 
 #include "chrome/browser/metrics/metrics_services_manager.h"
 
+#include <string>
+
 #include "base/command_line.h"
+#include "base/guid.h"
+#include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/metrics/chrome_metrics_service_client.h"
 #include "chrome/browser/metrics/variations/variations_service.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
+#include "chrome/installer/util/google_update_settings.h"
 #include "components/metrics/metrics_service.h"
 #include "components/metrics/metrics_state_manager.h"
 #include "components/rappor/rappor_service.h"
@@ -18,6 +23,47 @@
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #endif
 
+namespace {
+
+// Returns the client info returned by
+// GoogleUpdateSettings::LoadMetricsClientInfo. Also migrates old client id
+// formats to the new one.
+scoped_ptr<metrics::ClientInfo> LoadMetricsClientInfo() {
+  scoped_ptr<metrics::ClientInfo> client_info =
+      GoogleUpdateSettings::LoadMetricsClientInfo();
+
+  // Prior to 2014-07, the client ID was stripped of its dashes before being
+  // saved. Migrate back to a proper GUID if this is the case. This migration
+  // code below can be removed in M41+.
+  const size_t kGUIDLengthWithoutDashes = 32U;
+  if (client_info &&
+      client_info->client_id.length() == kGUIDLengthWithoutDashes) {
+    DCHECK(client_info->client_id.find('-') == std::string::npos);
+
+    std::string client_id_with_dashes;
+    client_id_with_dashes.reserve(kGUIDLengthWithoutDashes + 4U);
+    std::string::const_iterator client_id_it = client_info->client_id.begin();
+    for (size_t i = 0; i < kGUIDLengthWithoutDashes + 4U; ++i) {
+      if (i == 8U || i == 13U || i == 18U || i == 23U) {
+        client_id_with_dashes.push_back('-');
+      } else {
+        client_id_with_dashes.push_back(*client_id_it);
+        ++client_id_it;
+      }
+    }
+    DCHECK(client_id_it == client_info->client_id.end());
+    client_info->client_id.assign(client_id_with_dashes);
+  }
+
+  // The GUID retrieved (and possibly fixed above) should be valid unless
+  // retrieval failed.
+  DCHECK(!client_info || base::IsValidGUID(client_info->client_id));
+
+  return client_info.Pass();
+}
+
+}  // namespace
+
 MetricsServicesManager::MetricsServicesManager(PrefService* local_state)
     : local_state_(local_state) {
   DCHECK(local_state);
@@ -70,7 +116,9 @@ metrics::MetricsStateManager* MetricsServicesManager::GetMetricsStateManager() {
     metrics_state_manager_ = metrics::MetricsStateManager::Create(
         local_state_,
         base::Bind(&MetricsServicesManager::IsMetricsReportingEnabled,
-                   base::Unretained(this)));
+                   base::Unretained(this)),
+        base::Bind(&GoogleUpdateSettings::StoreMetricsClientInfo),
+        base::Bind(&LoadMetricsClientInfo));
   }
   return metrics_state_manager_.get();
 }