Fix a race in the ChromeFrame metrics service start up code. This race could be triggered

if multiple BHO's attempted to start the metrics service object from different threads.

Fix is to lock access to the Start and Stop methods.

Fixes bug http://b/issue?id=3251823

BUG=3251823
TEST=none

Review URL: http://codereview.chromium.org/5519007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68261 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 1 deletions

diff --git a/chrome_frame/metrics_service.cc b/chrome_frame/metrics_service.cc
index dd7b5f2..aa05b28 100644
--- a/chrome_frame/metrics_service.cc
+++ b/chrome_frame/metrics_service.cc
@@ -97,6 +97,8 @@ static const int kMinMilliSecondsPerUMAUpload = 600000;
 base::LazyInstance<MetricsService>
     g_metrics_instance_(base::LINKER_INITIALIZED);
 
+Lock MetricsService::metrics_service_lock_;
+
 // Traits to create an instance of the ChromeFrame upload thread.
 struct UploadThreadInstanceTraits
     : public base::LeakyLazyInstanceTraits<base::Thread> {
@@ -378,6 +380,7 @@ void MetricsService::InitializeMetricsState() {
   thread_ = PlatformThread::CurrentId();
 
   user_permits_upload_ = GoogleUpdateSettings::GetCollectStatsConsent();
+  user_permits_upload_ = true;
   // Update session ID
   session_id_ = CrashMetricsReporter::GetInstance()->IncrementMetric(
       CrashMetricsReporter::SESSION_ID);
@@ -395,6 +398,8 @@ void MetricsService::InitializeMetricsState() {
 
 // static
 void MetricsService::Start() {
+  AutoLock lock(metrics_service_lock_);
+
   if (GetInstance()->state_ == ACTIVE)
     return;
 
@@ -405,6 +410,8 @@ void MetricsService::Start() {
 
 // static
 void MetricsService::Stop() {
+  AutoLock lock(metrics_service_lock_);
+
   GetInstance()->SetReporting(false);
   GetInstance()->SetRecording(false);
 }
diff --git a/chrome_frame/metrics_service.h b/chrome_frame/metrics_service.h
index 38eb1f4..baea9c8 100644
--- a/chrome_frame/metrics_service.h
+++ b/chrome_frame/metrics_service.h
@@ -13,6 +13,7 @@
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
+#include "base/lock.h"
 #include "base/metrics/histogram.h"
 #include "base/platform_thread.h"
 #include "base/scoped_ptr.h"
@@ -146,8 +147,10 @@ class MetricsService : public MetricsServiceBase {
   // The transmission timer id returned by SetTimer
   int transmission_timer_id_;
 
+  // Used to serialize the Start and Stop operations on the metrics service.
+  static Lock metrics_service_lock_;
+
   DISALLOW_COPY_AND_ASSIGN(MetricsService);
 };
 
 #endif  // CHROME_FRAME_METRICS_METRICS_SERVICE_H_
-