Add a ConvertableToTraceFormat type to the trace framework.

base/debug/trace_event_impl.cc

Index: base/debug/trace_event_impl.cc
diff --git a/base/debug/trace_event_impl.cc b/base/debug/trace_event_impl.cc
index 871ac9c43b13208791a9aa499dcee0b8c76e2c86..f525d7ce31ec52dab9c80ec8ca70c898fa9f706e 100644
--- a/base/debug/trace_event_impl.cc
+++ b/base/debug/trace_event_impl.cc
@@ -264,17 +264,19 @@ TraceEvent::TraceEvent()
   memset(arg_values_, 0, sizeof(arg_values_));
 }
 
-TraceEvent::TraceEvent(int thread_id,
-                       TimeTicks timestamp,
-                       char phase,
-                       const unsigned char* category_enabled,
-                       const char* name,
-                       unsigned long long id,
-                       int num_args,
-                       const char** arg_names,
-                       const unsigned char* arg_types,
-                       const unsigned long long* arg_values,
-                       unsigned char flags)
+TraceEvent::TraceEvent(
+    int thread_id,
+    TimeTicks timestamp,
+    char phase,
+    const unsigned char* category_enabled,
+    const char* name,
+    unsigned long long id,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    scoped_ptr<ConvertableToTraceFormat> convertable_values[],
+    unsigned char flags)
     : timestamp_(timestamp),
       id_(id),
       category_enabled_(category_enabled),
@@ -287,12 +289,17 @@ TraceEvent::TraceEvent(int thread_id,
   int i = 0;
   for (; i < num_args; ++i) {
     arg_names_[i] = arg_names[i];
-    arg_values_[i].as_uint = arg_values[i];
     arg_types_[i] = arg_types[i];
+
+    if (arg_types[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+      convertable_values_[i].reset(convertable_values[i].release());
+    else
+      arg_values_[i].as_uint = arg_values[i];
   }
   for (; i < kTraceMaxNumArgs; ++i) {
     arg_names_[i] = NULL;
     arg_values_[i].as_uint = 0u;
+    convertable_values_[i].reset();
     arg_types_[i] = TRACE_VALUE_TYPE_UINT;
   }
 
@@ -309,6 +316,10 @@ TraceEvent::TraceEvent(int thread_id,
 
   bool arg_is_copy[kTraceMaxNumArgs];
   for (i = 0; i < num_args; ++i) {
+    // No copying of convertable types, we retain ownership.
+    if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+      continue;
+
     // We only take a copy of arg_vals if they are of type COPY_STRING.
     arg_is_copy[i] = (arg_types_[i] == TRACE_VALUE_TYPE_COPY_STRING);
     if (arg_is_copy[i])
@@ -322,10 +333,15 @@ TraceEvent::TraceEvent(int thread_id,
     const char* end = ptr + alloc_size;
     if (copy) {
       CopyTraceEventParameter(&ptr, &name_, end);
-      for (i = 0; i < num_args; ++i)
+      for (i = 0; i < num_args; ++i) {
+        if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+          continue;
         CopyTraceEventParameter(&ptr, &arg_names_[i], end);
+      }
     }
     for (i = 0; i < num_args; ++i) {
+      if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+        continue;
       if (arg_is_copy[i])
         CopyTraceEventParameter(&ptr, &arg_values_[i].as_string, end);
     }
@@ -333,6 +349,58 @@ TraceEvent::TraceEvent(int thread_id,
   }
 }
 
+TraceEvent::TraceEvent(const TraceEvent& other)
+    : timestamp_(other.timestamp_),
+      id_(other.id_),
+      category_enabled_(other.category_enabled_),
+      name_(other.name_),
+      thread_id_(other.thread_id_),
+      phase_(other.phase_),
+      flags_(other.flags_) {
+  parameter_copy_storage_ = other.parameter_copy_storage_;
+
+  for (int i = 0; i < kTraceMaxNumArgs; ++i) {
+    arg_values_[i] = other.arg_values_[i];
+    arg_names_[i] = other.arg_names_[i];
+    arg_types_[i] = other.arg_types_[i];
+
+    if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE) {
+      convertable_values_[i].reset(
+          const_cast<TraceEvent*>(&other)->convertable_values_[i].release());
+    } else {
+      convertable_values_[i].reset();
+    }
+  }
+}
+
+TraceEvent& TraceEvent::operator=(const TraceEvent& other) {
+  if (this == &other)
+    return *this;
+
+  timestamp_ = other.timestamp_;
+  id_ = other.id_;
+  category_enabled_ = other.category_enabled_;
+  name_ = other.name_;
+  parameter_copy_storage_ = other.parameter_copy_storage_;
+  thread_id_ = other.thread_id_;
+  phase_ = other.phase_;
+  flags_ = other.flags_;
+
+  for (int i = 0; i < kTraceMaxNumArgs; ++i) {
+    arg_values_[i] = other.arg_values_[i];
+    arg_names_[i] = other.arg_names_[i];
+    arg_types_[i] = other.arg_types_[i];
+
+    if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE) {
+      convertable_values_[i].reset(
+          const_cast<TraceEvent*>(&other)->convertable_values_[i].release());
+    } else {
+      convertable_values_[i].reset();
+    }
+  }
+  return *this;
+}
+
 TraceEvent::~TraceEvent() {
 }
 
@@ -403,7 +471,11 @@ void TraceEvent::AppendAsJSON(std::string* out) const {
     *out += "\"";
     *out += arg_names_[i];
     *out += "\":";
-    AppendValueAsJSON(arg_types_[i], arg_values_[i], out);
+
+    if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+      convertable_values_[i]->AppendAsTraceFormat(out);
+    else
+      AppendValueAsJSON(arg_types_[i], arg_values_[i], out);
   }
   *out += "}";
 
@@ -565,13 +637,7 @@ void TraceSamplingThread::DefaultSampleCallback(TraceBucketData* bucket_data) {
   ExtractCategoryAndName(combined, &category, &name);
   TRACE_EVENT_API_ADD_TRACE_EVENT(TRACE_EVENT_PHASE_SAMPLE,
                                   TraceLog::GetCategoryEnabled(category),
-                                  name,
-                                  0,
-                                  0,
-                                  NULL,
-                                  NULL,
-                                  NULL,
-                                  0);
+                                  name, 0, 0, NULL, NULL, NULL, NULL, 0);
 }
 
 void TraceSamplingThread::GetSamples() {
@@ -1014,20 +1080,23 @@ void TraceLog::Flush(const TraceLog::OutputCallback& cb) {
   }
 }
 
-void TraceLog::AddTraceEvent(char phase,
-                             const unsigned char* category_enabled,
-                             const char* name,
-                             unsigned long long id,
-                             int num_args,
-                             const char** arg_names,
-                             const unsigned char* arg_types,
-                             const unsigned long long* arg_values,
-                             unsigned char flags) {
+void TraceLog::AddTraceEvent(
+    char phase,
+    const unsigned char* category_enabled,
+    const char* name,
+    unsigned long long id,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    scoped_ptr<ConvertableToTraceFormat> convertable_values[],
+    unsigned char flags) {
   int thread_id = static_cast<int>(base::PlatformThread::CurrentId());
   base::TimeTicks now = base::TimeTicks::NowFromSystemTraceTime();
   AddTraceEventWithThreadIdAndTimestamp(phase, category_enabled, name, id,
                                         thread_id, now, num_args, arg_names,
-                                        arg_types, arg_values, flags);
+                                        arg_types, arg_values,
+                                        convertable_values, flags);
 }
 
 void TraceLog::AddTraceEventWithThreadIdAndTimestamp(
@@ -1041,6 +1110,7 @@ void TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     const char** arg_names,
     const unsigned char* arg_types,
     const unsigned long long* arg_values,
+    scoped_ptr<ConvertableToTraceFormat> convertable_values[],
     unsigned char flags) {
   DCHECK(name);
 
@@ -1097,7 +1167,7 @@ void TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     logged_events_->AddEvent(TraceEvent(thread_id,
         now, phase, category_enabled, name, id,
         num_args, arg_names, arg_types, arg_values,
-        flags));
+        convertable_values, flags));
 
     if (logged_events_->IsFull())
       notifier.AddNotificationWhileLocked(TRACE_BUFFER_FULL);
@@ -1184,7 +1254,7 @@ void TraceLog::AddThreadNameMetadataEvents() {
           TimeTicks(), TRACE_EVENT_PHASE_METADATA,
           &g_category_enabled[g_category_metadata],
           "thread_name", trace_event_internal::kNoEventId,
-          num_args, &arg_name, &arg_type, &arg_value,
+          num_args, &arg_name, &arg_type, &arg_value, NULL,
           TRACE_EVENT_FLAG_NONE));
     }
   }
@@ -1244,6 +1314,7 @@ ScopedTrace::ScopedTrace(
         NULL,                       // arg_names
         NULL,                       // arg_types
         NULL,                       // arg_values
+        NULL,                       // convertable_values
         TRACE_EVENT_FLAG_NONE);     // flags
   } else {
     category_enabled_ = NULL;
@@ -1261,6 +1332,7 @@ ScopedTrace::~ScopedTrace() {
         NULL,                    // arg_names
         NULL,                    // arg_types
         NULL,                    // arg_values
+        NULL,                    // convertable values
         TRACE_EVENT_FLAG_NONE);  // flags
   }
 }