Refactor trace_event_impl's SetEnabled to use TraceOptions. Propagate this through the whole stack.

components/tracing/child_trace_message_filter.h

 // Copyright (c) 2012 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 COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_
 #define COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_
 
 #include "base/bind.h"
 #include "base/memory/ref_counted_memory.h"
 #include "ipc/message_filter.h"
@@ skipping 14 matching lines @@
   virtual void OnFilterRemoved() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
  protected:
   virtual ~ChildTraceMessageFilter();
 
  private:
   // Message handlers.
   void OnBeginTracing(const std::string& category_filter_str,
                       base::TimeTicks browser_time,
-                      int options);
+                      const std::string& options);
   void OnEndTracing();
   void OnEnableMonitoring(const std::string& category_filter_str,
                           base::TimeTicks browser_time,
-                          int options);
+                          const std::string& options);
   void OnDisableMonitoring();
   void OnCaptureMonitoringSnapshot();
   void OnGetTraceBufferPercentFull();
   void OnSetWatchEvent(const std::string& category_name,
                        const std::string& event_name);
   void OnCancelWatchEvent();
   void OnWatchEventMatched();
 
   // Callback from trace subsystem.
   void OnTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr,
       bool has_more_events);
 
   void OnMonitoringTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr,
       bool has_more_events);
 
   IPC::Sender* sender_;
   base::MessageLoopProxy* ipc_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildTraceMessageFilter);
 };
 
 }  // namespace tracing
 
 #endif  // COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_