Change base class of V8SamplingProfiler to AsyncEnabledStateObserver.

content/renderer/devtools/v8_sampling_profiler.h

Index: content/renderer/devtools/v8_sampling_profiler.h
diff --git a/content/renderer/devtools/v8_sampling_profiler.h b/content/renderer/devtools/v8_sampling_profiler.h
index 7604f5a2feec49c1610fbb792e0567dc8f1d23a8..efa1735bb6d039751c69c014e196c5f8c35578a6 100644
--- a/content/renderer/devtools/v8_sampling_profiler.h
+++ b/content/renderer/devtools/v8_sampling_profiler.h
@@ -21,7 +21,7 @@ class V8SamplingThread;
 // The class monitors enablement of V8 CPU profiler and
 // spawns a sampling thread when needed.
 class CONTENT_EXPORT V8SamplingProfiler final
-    : public base::trace_event::TraceLog::EnabledStateObserver {
+    : public base::trace_event::TraceLog::AsyncEnabledStateObserver {
  public:
   explicit V8SamplingProfiler(bool underTest = false);
   ~V8SamplingProfiler() override;
@@ -41,6 +41,7 @@ class CONTENT_EXPORT V8SamplingProfiler final
   std::unique_ptr<V8SamplingThread> sampling_thread_;
   std::unique_ptr<Sampler> render_thread_sampler_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  base::WeakPtrFactory<V8SamplingProfiler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(V8SamplingProfiler);
 };