Move SystemLogsSource class into new file

chrome/browser/chromeos/system_logs/single_debug_daemon_log_source.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SINGLE_DEBUG_DAEMON_LOG_SOURCE_H_
 #define CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SINGLE_DEBUG_DAEMON_LOG_SOURCE_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
-#include "chrome/browser/feedback/system_logs/system_logs_fetcher.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/feedback/system_logs/system_logs_source.h"
 
 namespace system_logs {
 
 // Gathers log data from a single debugd log source, via DebugDaemonClient.
 class SingleDebugDaemonLogSource : public SystemLogsSource {
  public:
   enum class SupportedSource {
     // For "modetest" command.
     kModetest,
 
@@ skipping 15 matching lines @@
                        const std::string& result) const;
 
   base::WeakPtrFactory<SingleDebugDaemonLogSource> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleDebugDaemonLogSource);
 };
 
 }  // namespace system_logs
 
 #endif  // CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SINGLE_DEBUG_DAEMON_LOG_SOURCE_H_