[tracing] Add thread name to the pseudo stack of heap profiler

content/browser/browser_main_runner.cc

Index: content/browser/browser_main_runner.cc
diff --git a/content/browser/browser_main_runner.cc b/content/browser/browser_main_runner.cc
index ef2fcb08fdb929421f9fd56eed0cb9d8b3ddb911..de130940eff672b3df28563ea4c60f4933ffab6a 100644
--- a/content/browser/browser_main_runner.cc
+++ b/content/browser/browser_main_runner.cc
@@ -15,6 +15,7 @@
 #include "base/profiler/scoped_profile.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/time/time.h"
+#include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 #include "base/trace_event/trace_event.h"
 #include "base/tracked_objects.h"
 #include "build/build_config.h"
@@ -44,6 +45,7 @@ namespace content {
 namespace {
 
 bool g_exited_main_message_loop = false;
+const char kMainThreadName[] = "CrBrowserMain";
 
 }  // namespace
 
@@ -63,7 +65,9 @@ class BrowserMainRunnerImpl : public BrowserMainRunner {
 
     // TODO(vadimt, yiyaoliu): Remove all tracked_objects references below once
     // crbug.com/453640 is fixed.
-    tracked_objects::ThreadData::InitializeThreadContext("CrBrowserMain");
+    tracked_objects::ThreadData::InitializeThreadContext(kMainThreadName);
+    base::trace_event::AllocationContextTracker::SetCurrentThreadName(

[petrcermak, 2016/03/29 13:07:47]

I think that it would be better to do this in ThreadIdNameManager::SetName.
After all, you already pass the thread name on line 68. That way, the code path
for setting the current thread name through AllocationContextTracker will be the
same on all processes.

[ssid, 2016/03/29 18:19:11]

Hm no. The main thread name is never set in ThreadIdNameManager. The line 68
refers to ThreadData which is different from ThreadIdNameManager. I cannot use
ThreadData because it doesn't get set in tests, so easier to use
ThreadIdNameManager (prefered by primiano@). So, I do not want to register the
main thread in ThreadIdNameManager for this reason, so setting it separately. 

+        kMainThreadName);
     TRACK_SCOPED_REGION(
         "Startup", "BrowserMainRunnerImpl::Initialize");
     TRACE_EVENT0("startup", "BrowserMainRunnerImpl::Initialize");