Implement tracing interface for v8

src/libplatform/default-platform.cc

Index: src/libplatform/default-platform.cc
diff --git a/src/libplatform/default-platform.cc b/src/libplatform/default-platform.cc
index 383d8ce1e0dc2d9394521cbc9ce5677890e7674f..e8c15572ad1106b97d161fad070dceeffdf6d25e 100644
--- a/src/libplatform/default-platform.cc
+++ b/src/libplatform/default-platform.cc
@@ -168,5 +168,30 @@ double DefaultPlatform::MonotonicallyIncreasingTime() {
   return base::TimeTicks::HighResolutionNow().ToInternalValue() /
          static_cast<double>(base::Time::kMicrosecondsPerSecond);
 }
+
+
+uint64_t DefaultPlatform::AddTraceEvent(
+    char phase, const uint8_t* category_enabled_flag, const char* name,
+    uint64_t id, uint64_t bind_id, int num_args, const char** arg_names,
+    const uint8_t* arg_types, const uint64_t* arg_values, unsigned int flags) {
+  return 0;
+}
+
+
+void DefaultPlatform::UpdateTraceEventDuration(
+    const uint8_t* category_enabled_flag, const char* name, uint64_t handle) {}
+
+
+const uint8_t* DefaultPlatform::GetCategoryGroupEnabled(const char* name) {
+  static uint8_t no = 0;
+  return &no;
+}
+
+
+const char* DefaultPlatform::GetCategoryGroupName(
+    const uint8_t* category_enabled_flag) {
+  static const char dummy[] = "dummy";
+  return dummy;
+}
 }  // namespace platform
 }  // namespace v8