Trace-based benchmarking via a mojo app.

mojo/common/tracing_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_COMMON_TRACING_IMPL_H_
 #define MOJO_COMMON_TRACING_IMPL_H_
 
 #include "base/macros.h"
 #include "mojo/public/cpp/application/interface_factory.h"
 #include "mojo/services/tracing/public/interfaces/tracing.mojom.h"
 
 namespace mojo {
 
 class ApplicationImpl;
 
 class TracingImpl : public InterfaceFactory<tracing::TraceProvider> {
  public:
   TracingImpl();
   ~TracingImpl() override;
 
   // This connects to the tracing service and registers ourselves to provide
   // tracing data on demand.
   void Initialize(ApplicationImpl* app);
 
+  void set_tracing_already_started(bool tracing_already_started) {
+    tracing_already_started_ = tracing_already_started;
+  }
+
  private:
   // InterfaceFactory<tracing::TraceProvider> implementation.
   void Create(ApplicationConnection* connection,
               InterfaceRequest<tracing::TraceProvider> request) override;
 
+  bool tracing_already_started_;
+
   DISALLOW_COPY_AND_ASSIGN(TracingImpl);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_COMMON_TRACING_IMPL_H_