Make JSONParser a pure interface.

components/safe_json/safe_json_parser_impl.h

Index: components/safe_json/safe_json_parser_impl.h
diff --git a/components/safe_json/safe_json_parser.h b/components/safe_json/safe_json_parser_impl.h
similarity index 58%
copy from components/safe_json/safe_json_parser.h
copy to components/safe_json/safe_json_parser_impl.h
index 8fb703b3e9a619f630906418841a8c87bd6d395f..99af9320e2402be0ce39745c8884f403fd97e680 100644
--- a/components/safe_json/safe_json_parser.h
+++ b/components/safe_json/safe_json_parser_impl.h
@@ -7,14 +7,14 @@
 
 #include <string>
 
-#include "base/basictypes.h"
-#include "base/callback.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "components/safe_json/safe_json_parser.h"
 #include "content/public/browser/utility_process_host_client.h"
 
 namespace base {
 class ListValue;
-class SingleThreadTaskRunner;
+class SequencedTaskRunner;
 class Value;
 }
 
@@ -24,22 +24,15 @@ class Message;
 
 namespace safe_json {
 
-// SafeJsonParser parses a given JSON safely via a utility process. The object
-// is ref-counted and kept alive after Start() is called until one of the two
-// callbacks is called.
-class SafeJsonParser : public content::UtilityProcessHostClient {
+class SafeJsonParserImpl : public content::UtilityProcessHostClient,
+                           public SafeJsonParser {
  public:
-  typedef base::Callback<void(scoped_ptr<base::Value>)> SuccessCallback;
-  typedef base::Callback<void(const std::string&)> ErrorCallback;
-
-  SafeJsonParser(const std::string& unsafe_json,
-                 const SuccessCallback& success_callback,
-                 const ErrorCallback& error_callback);
-
-  void Start();
+  SafeJsonParserImpl(const std::string& unsafe_json,
+                     const SuccessCallback& success_callback,
+                     const ErrorCallback& error_callback);
 
  private:
-  ~SafeJsonParser() override;
+  ~SafeJsonParserImpl() override;
 
   void StartWorkOnIOThread();
 
@@ -52,15 +45,18 @@ class SafeJsonParser : public content::UtilityProcessHostClient {
   // Implementing pieces of the UtilityProcessHostClient interface.
   bool OnMessageReceived(const IPC::Message& message) override;
 
+  // SafeJsonParser implementation.
+  void Start() override;
+
   const std::string unsafe_json_;
   SuccessCallback success_callback_;
   ErrorCallback error_callback_;
-  scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> caller_task_runner_;
 
   scoped_ptr<base::Value> parsed_json_;
   std::string error_;
 
-  DISALLOW_COPY_AND_ASSIGN(SafeJsonParser);
+  DISALLOW_COPY_AND_ASSIGN(SafeJsonParserImpl);
 };
 
 }  // namespace safe_json