Implement tracing interface for v8

include/v8-platform.h

Index: include/v8-platform.h
diff --git a/include/v8-platform.h b/include/v8-platform.h
index c6cba0f982929aa8795e214c89f9fc1adc4ffb11..13afa889c726394e375a95920438323e3c1a65c1 100644
--- a/include/v8-platform.h
+++ b/include/v8-platform.h
@@ -5,6 +5,8 @@
 #ifndef V8_V8_PLATFORM_H_
 #define V8_V8_PLATFORM_H_
 
+#include <stdint.h>
+
 namespace v8 {
 
 class Isolate;
@@ -107,6 +109,32 @@ class Platform {
    * the epoch.
    **/
   virtual double MonotonicallyIncreasingTime() = 0;
+
+  /**
+   * Get a pointer to the enabled state of the given trace category.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) = 0;
+
+  /**
+   * Get the category group name of the given category_enabled_flags.
+   **/
+  virtual const char* GetCategoryGroupName(
+      const uint8_t* category_enabled_flag) = 0;
+
+  /**
+   * Add a trace event to the platform tracing system.

[Yang, 2015/11/19 09:30:32]

Can you add a comment about what this method returns? It seems unclear to me.

[fmeawad, 2015/11/20 22:22:20]

I have updated the description on all the methods.

+   **/
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      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) = 0;
+
+  /**
+   * Set the duration field of a COMPLETE trace event.
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) = 0;
 };
 
 }  // namespace v8