Avoid calling strlen() where possible in base/trace_config

chrome/browser/chromeos/arc/tracing/arc_tracing_bridge.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 "chrome/browser/chromeos/arc/tracing/arc_tracing_bridge.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/arc/arc_bridge_service.h"
@@ skipping 65 matching lines @@
   if (!tracing_instance) {
     // Use PostTask as the convention of TracingAgent. The caller expects
     // callback to be called after this function returns.
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback, false));
     return;
   }
 
   std::vector<std::string> selected_categories;
   for (const auto& category : categories_) {
-    if (trace_config.IsCategoryGroupEnabled(category.full_name.c_str()))
+    if (trace_config.IsCategoryGroupEnabled(category.full_name))
       selected_categories.push_back(category.name);
   }
 
   tracing_instance->StartTracing(selected_categories, callback);
 }
 
 void ArcTracingBridge::StopTracing(const StopTracingCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   mojom::TracingInstance* tracing_instance =
       ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service()->tracing(), StopTracing);
   if (!tracing_instance) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback, false));
     return;
   }
   tracing_instance->StopTracing(callback);
 }
 
 }  // namespace arc