Revert of [tracing] Support ConvertableToTraceFormat argument type.

include/v8-platform.h

 // Copyright 2013 the V8 project 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 V8_V8_PLATFORM_H_
 #define V8_V8_PLATFORM_H_
 
 #include <stddef.h>
 #include <stdint.h>
-#include <memory>
-#include <string>
 
 namespace v8 {
 
 class Isolate;
 
 /**
  * A Task represents a unit of work.
  */
 class Task {
  public:
-  virtual ~Task() = default;
+  virtual ~Task() {}
 
   virtual void Run() = 0;
 };
 
+
 /**
- * An IdleTask represents a unit of work to be performed in idle time.
- * The Run method is invoked with an argument that specifies the deadline in
- * seconds returned by MonotonicallyIncreasingTime().
- * The idle task is expected to complete by this deadline.
- */
+* An IdleTask represents a unit of work to be performed in idle time.
+* The Run method is invoked with an argument that specifies the deadline in
+* seconds returned by MonotonicallyIncreasingTime().
+* The idle task is expected to complete by this deadline.
+*/
 class IdleTask {
  public:
-  virtual ~IdleTask() = default;
+  virtual ~IdleTask() {}
   virtual void Run(double deadline_in_seconds) = 0;
 };
 
-/**
- * The interface represents complex arguments to trace events.
- */
-class ConvertableToTraceFormat {
- public:
-  virtual ~ConvertableToTraceFormat() = default;
-
-  /**
-   * Append the class info to the provided |out| string. The appended
-   * data must be a valid JSON object. Strings must be properly quoted, and
-   * escaped. There is no processing applied to the content after it is
-   * appended.
-   */
-  virtual void AppendAsTraceFormat(std::string* out) const = 0;
-};
 
 /**
  * V8 Platform abstraction layer.
  *
  * The embedder has to provide an implementation of this interface before
  * initializing the rest of V8.
  */
 class Platform {
  public:
   /**
    * This enum is used to indicate whether a task is potentially long running,
    * or causes a long wait. The embedder might want to use this hint to decide
    * whether to execute the task on a dedicated thread.
    */
   enum ExpectedRuntime {
     kShortRunningTask,
     kLongRunningTask
   };
 
-  virtual ~Platform() = default;
+  virtual ~Platform() {}
 
   /**
    * Gets the number of threads that are used to execute background tasks. Is
    * used to estimate the number of tasks a work package should be split into.
    * A return value of 0 means that there are no background threads available.
    * Note that a value of 0 won't prohibit V8 from posting tasks using
    * |CallOnBackgroundThread|.
    */
   virtual size_t NumberOfAvailableBackgroundThreads() { return 0; }
 
@@ skipping 80 matching lines @@
    * tracing and the category of the particular trace are enabled. It is not
    * advisable to call this function on its own; it is really only meant to be
    * used by the trace macros. The returned handle can be used by
    * UpdateTraceEventDuration to update the duration of COMPLETE events.
    */
   virtual uint64_t AddTraceEvent(
       char phase, const uint8_t* category_enabled_flag, const char* name,
       const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
       const char** arg_names, const uint8_t* arg_types,
       const uint64_t* arg_values, unsigned int flags) {
-    return AddTraceEvent(phase, category_enabled_flag, name, scope, id, bind_id,
-                         num_args, arg_names, arg_types, arg_values, nullptr,
-                         flags);
-  }
-
-  /**
-   * Adds a trace event to the platform tracing system. This function call is
-   * usually the result of a TRACE_* macro from trace_event_common.h when
-   * tracing and the category of the particular trace are enabled. It is not
-   * advisable to call this function on its own; it is really only meant to be
-   * used by the trace macros. The returned handle can be used by
-   * UpdateTraceEventDuration to update the duration of COMPLETE events.
-   */
-  virtual uint64_t AddTraceEvent(
-      char phase, const uint8_t* category_enabled_flag, const char* name,
-      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
-      const char** arg_names, const uint8_t* arg_types,
-      const uint64_t* arg_values,
-      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
-      unsigned int flags) {
     return 0;
   }
 
   /**
    * Sets the duration field of a COMPLETE trace event. It must be called with
    * the handle returned from AddTraceEvent().
    **/
   virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
                                         const char* name, uint64_t handle) {}
 
   class TraceStateObserver {
    public:
     virtual ~TraceStateObserver() = default;
     virtual void OnTraceEnabled() = 0;
     virtual void OnTraceDisabled() = 0;
   };
 
   /** Adds tracing state change observer. */
   virtual void AddTraceStateObserver(TraceStateObserver*) {}
 
   /** Removes tracing state change observer. */
   virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
 };
 
 }  // namespace v8
 
 #endif  // V8_V8_PLATFORM_H_