Stack sampling profiler: handle unloaded and unloading modules

base/profiler/stack_sampling_profiler.h

Index: base/profiler/stack_sampling_profiler.h
diff --git a/base/profiler/stack_sampling_profiler.h b/base/profiler/stack_sampling_profiler.h
index 9aa9c31d67afd31a12113f5caeeb1b53e3ae771e..e9b1804bbf282ee3cbc0d7764d306d6b563f4e41 100644
--- a/base/profiler/stack_sampling_profiler.h
+++ b/base/profiler/stack_sampling_profiler.h
@@ -20,6 +20,7 @@
 namespace base {
 
 class NativeStackSampler;
+class NativeStackSamplerTestDelegate;
 
 // StackSamplingProfiler periodically stops a thread to sample its stack, for
 // the purpose of collecting information about which code paths are
@@ -156,10 +157,15 @@ class BASE_EXPORT StackSamplingProfiler {
   // thread-safe callback implementation.
   using CompletedCallback = Callback<void(const CallStackProfiles&)>;
 
-  // Creates a profiler that sends completed profiles to |callback|.
+  // Creates a profiler that sends completed profiles to |callback|. The second
+  // constructor is for test purposes.
   StackSamplingProfiler(PlatformThreadId thread_id,
                         const SamplingParams& params,
                         const CompletedCallback& callback);
+  StackSamplingProfiler(PlatformThreadId thread_id,
+                        const SamplingParams& params,
+                        const CompletedCallback& callback,
+                        NativeStackSamplerTestDelegate* test_delegate);
   // Stops any profiling currently taking place before destroying the profiler.
   ~StackSamplingProfiler();
 
@@ -231,6 +237,9 @@ class BASE_EXPORT StackSamplingProfiler {
 
   const CompletedCallback completed_callback_;
 
+  // Stored until it can be passed to the NativeStackSampler created in Start().
+  NativeStackSamplerTestDelegate* const test_delegate_;
+
   DISALLOW_COPY_AND_ASSIGN(StackSamplingProfiler);
 };