Sampling profiling thread should be joined in a FILE thread

chrome/test/base/tracing.cc

Index: chrome/test/base/tracing.cc
diff --git a/chrome/test/base/tracing.cc b/chrome/test/base/tracing.cc
index 5aa07e7e4d6f287e8de7564f6a258e09dd087e63..cba039b6663de958095f728b6f0d7f8967691a91 100644
--- a/chrome/test/base/tracing.cc
+++ b/chrome/test/base/tracing.cc
@@ -34,7 +34,6 @@ class InProcessTraceController {
     return content::TracingController::GetInstance()->EnableRecording(
         category_patterns, content::TracingController::DEFAULT_OPTIONS,
         content::TracingController::EnableRecordingDoneCallback());
-    return true;
   }
 
   bool BeginTracingWithWatch(const std::string& category_patterns,
@@ -44,11 +43,20 @@ class InProcessTraceController {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     DCHECK(num_occurrences > 0);
     watch_notification_count_ = num_occurrences;
-    return content::TracingController::GetInstance()->SetWatchEvent(
+    if (!content::TracingController::GetInstance()->SetWatchEvent(
         category_name, event_name,
         base::Bind(&InProcessTraceController::OnWatchEventMatched,
-                   base::Unretained(this))) &&
-        BeginTracing(category_patterns);
+                   base::Unretained(this))))

[Paweł Hajdan Jr., 2014/01/02 12:27:23]

nit: This should have braces {} because condition spans several lines.

+      return false;
+    if (!content::TracingController::GetInstance()->EnableRecording(
+        category_patterns, content::TracingController::DEFAULT_OPTIONS,

[Paweł Hajdan Jr., 2014/01/02 12:27:23]

nit: Please indent this +4 and add braces {}.

+        base::Bind(&InProcessTraceController::OnEnableTracingComplete,
+                   base::Unretained(this))))
+      return false;
+
+    message_loop_runner_ = new content::MessageLoopRunner;
+    message_loop_runner_->Run();
+    return true;
   }
 
   bool WaitForWatchEvent(base::TimeDelta timeout) {
@@ -93,6 +101,10 @@ class InProcessTraceController {
  private:
   friend struct DefaultSingletonTraits<InProcessTraceController>;
 
+  void OnEnableTracingComplete() {
+    message_loop_runner_->Quit();
+  }
+
   void OnEndTracingComplete() {
     message_loop_runner_->Quit();
   }