Test virtual interface [NOT FOR REVIEW]

components/tracing/test/tracing_interface_simulator.cc

+// Copyright 2017 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.
+
+#include "tracing_interface_simulator.h"
+
+#include <string.h>
+
+#include "base/trace_event/trace_event.h"
+
+namespace tracing {
+
+namespace {
+
+class TracingImplementation;
+
+bool g_category_test = true;
+TracingImplementation *g_instance;
+
+class TracingImplementation : public TracingInterface {
+ public:
+  void AddEvent(const char *category, char type,
+                const char *name, bool copy_name) const override {
+    TRACE_EVENT0(category, name);

[Primiano Tucci (use gerrit), 2017/01/27 21:26:10]

this is over-penalizing this case. if you use a trace_event0 you will get
another category check and another jump here.

+  }
+
+  const bool* GetPointerForCategory(const char *category) const override {
+    if (::strcmp(category, "test_category") == 0)

[Primiano Tucci (use gerrit), 2017/01/27 21:26:10]

base::trace_event::TraceLog::GetCategoryGroupEnabled

+      return &g_category_test;
+    CHECK(false);
+    return nullptr;
+  }
+};
+
+}  // namespace
+
+void InitTracingInterface() {
+  g_instance = new TracingImplementation();
+}
+
+const TracingInterface* GetTracingInterface() {
+  return g_instance;
+}
+
+void AddEventDirect(const char *category, char type,
+                    const char *name, bool copy_name) {
+  TRACE_EVENT0(category, name);
+}
+
+const bool* GetPointerForCategoryDirect(const char *category) {
+  if (::strcmp(category, "test_category") == 0)
+    return &g_category_test;
+  CHECK(false);
+  return nullptr;
+}
+
+}  // namespace tracing