Query NaCl processes' GDB debug port on the correct thread.

chrome/browser/task_manager/sampling/task_group.cc

Index: chrome/browser/task_manager/sampling/task_group.cc
diff --git a/chrome/browser/task_manager/sampling/task_group.cc b/chrome/browser/task_manager/sampling/task_group.cc
index d7fab26f8d64944db4aa3da4f1b4d03a783e06c9..b40efde410d16c701063325cf13650ca05a46533 100644
--- a/chrome/browser/task_manager/sampling/task_group.cc
+++ b/chrome/browser/task_manager/sampling/task_group.cc
@@ -90,7 +90,7 @@ TaskGroup::TaskGroup(
       user_peak_handles_(-1),
 #endif  // defined(OS_WIN)
 #if !defined(DISABLE_NACL)
-      nacl_debug_stub_port_(-1),
+      nacl_debug_stub_port_(nacl::kGdbDebugStubPortUnknown),
 #endif  // !defined(DISABLE_NACL)
       idle_wakeups_per_second_(-1),
 #if defined(OS_LINUX)
@@ -182,6 +182,7 @@ void TaskGroup::Refresh(const gpu::VideoMemoryUsageStats& gpu_memory_stats,
 #if !defined(DISABLE_NACL)
   if (TaskManagerObserver::IsResourceRefreshEnabled(REFRESH_TYPE_NACL,
                                                     refresh_flags) &&
+      nacl_debug_stub_port_ == nacl::kGdbDebugStubPortUnknown &&

[Wez, 2017/01/20 03:25:28]

bradnelson: I thought of adding this, but I think for it to work we would need
NaClBrowser to return Unknown for the port number until the process checks-in,
because of async port allocation under Windows - we'd probably want to hard-wire
non-NACL process types to Unused and update the GetDebugGdbStubPort() API to
return Unknown rather than Unused. Probably not worth optimizing this, though..
:P

       !tasks_.empty()) {
     RefreshNaClDebugStubPort(tasks_[0]->GetChildProcessUniqueID());
   }
@@ -258,12 +259,15 @@ void TaskGroup::RefreshWindowsHandles() {
 }
 
 #if !defined(DISABLE_NACL)
+static int GetNaClDebugStubPort(int process_id) {
+  return nacl::NaClBrowser::GetInstance()->GetProcessGdbDebugStubPort(
+      process_id);
+}
+
 void TaskGroup::RefreshNaClDebugStubPort(int child_process_unique_id) {
-  nacl::NaClBrowser* nacl_browser = nacl::NaClBrowser::GetInstance();
   content::BrowserThread::PostTaskAndReplyWithResult(
       content::BrowserThread::IO, FROM_HERE,
-      base::Bind(&nacl::NaClBrowser::GetProcessGdbDebugStubPort,
-                 base::Unretained(nacl_browser), child_process_unique_id),
+      base::Bind(&GetNaClDebugStubPort, child_process_unique_id),
       base::Bind(&TaskGroup::OnRefreshNaClDebugStubPortDone,
                  weak_ptr_factory_.GetWeakPtr()));
 }