Support parallel captures from the StackSamplingProfiler.

base/profiler/native_stack_sampler_win.cc

Index: base/profiler/native_stack_sampler_win.cc
diff --git a/base/profiler/native_stack_sampler_win.cc b/base/profiler/native_stack_sampler_win.cc
index e1605109fe960d769523733b2a1190700b250d28..b1b5f4a38ea23b2170ca8f531602cffd32675d33 100644
--- a/base/profiler/native_stack_sampler_win.cc
+++ b/base/profiler/native_stack_sampler_win.cc
@@ -326,7 +326,7 @@ bool PointsToGuardPage(uintptr_t stack_pointer) {
 // ScopedSuspendThread scope, including indirectly via use of DCHECK/CHECK or
 // other logging statements. Otherwise this code can deadlock on heap locks in
 // the default heap acquired by the target thread before it was suspended.
-void SuspendThreadAndRecordStack(
+NativeStackSampler::ThreadState SuspendThreadAndRecordStack(
     HANDLE thread_handle,
     const void* base_address,
     void* stack_copy_buffer,
@@ -349,10 +349,11 @@ void SuspendThreadAndRecordStack(
     ScopedSuspendThread suspend_thread(thread_handle);
 
     if (!suspend_thread.was_successful())
-      return;
+      return NativeStackSampler::THREAD_UNSUSPENDABLE;
 
     if (!::GetThreadContext(thread_handle, &thread_context))
-      return;
+      return NativeStackSampler::THREAD_NO_INFO;
+
 #if defined(_WIN64)
     bottom = thread_context.Rsp;
 #else
@@ -360,13 +361,13 @@ void SuspendThreadAndRecordStack(
 #endif
 
     if ((top - bottom) > stack_copy_buffer_size)
-      return;
+      return NativeStackSampler::THREAD_STACK_TOO_BIG;
 
     // Dereferencing a pointer in the guard page in a thread that doesn't own
     // the stack results in a STATUS_GUARD_PAGE_VIOLATION exception and a crash.
     // This occurs very rarely, but reliably over the population.
     if (PointsToGuardPage(bottom))
-      return;
+      return NativeStackSampler::THREAD_INACCESSIBLE;
 
     (*annotator)(sample);
 
@@ -380,6 +381,7 @@ void SuspendThreadAndRecordStack(
   RewritePointersToStackMemory(top, bottom, &thread_context, stack_copy_buffer);
 
   RecordStack(&thread_context, stack);
+  return NativeStackSampler::THREAD_RUNNING;
 }
 
 // NativeStackSamplerWin ------------------------------------------------------
@@ -477,11 +479,18 @@ void NativeStackSamplerWin::RecordStackSample(
   if (!stack_copy_buffer_)
     return;
 
+  if (thread_state() == THREAD_EXITED)
+    return;
+
   std::vector<RecordedFrame> stack;
-  SuspendThreadAndRecordStack(thread_handle_.Get(), thread_stack_base_address_,
-                              stack_copy_buffer_.get(), kStackCopyBufferSize,
-                              &stack, annotator_, sample, test_delegate_);
+  set_thread_state(SuspendThreadAndRecordStack(
+      thread_handle_.Get(), thread_stack_base_address_,
+      stack_copy_buffer_.get(), kStackCopyBufferSize, &stack, annotator_,
+      sample, test_delegate_));
   CopyToSample(stack, sample, current_modules_);
+
+  if (test_delegate_)
+    test_delegate_->OnPostRecordSample(thread_state());
 }
 
 void NativeStackSamplerWin::ProfileRecordingStopped() {