Added an extra sync token field for extra command buffer identification.

gpu/ipc/gpu_command_buffer_traits.cc

Index: gpu/ipc/gpu_command_buffer_traits.cc
diff --git a/gpu/ipc/gpu_command_buffer_traits.cc b/gpu/ipc/gpu_command_buffer_traits.cc
index a1932eede1b2da38e83a031047c77c801409d6ff..c8560c3e844d586a89c1a05ba01110064b168383 100644
--- a/gpu/ipc/gpu_command_buffer_traits.cc
+++ b/gpu/ipc/gpu_command_buffer_traits.cc
@@ -59,6 +59,7 @@ void ParamTraits<gpu::SyncToken>::Write(Message* m, const param_type& p) {
 
   WriteParam(m, p.verified_flush());
   WriteParam(m, p.namespace_id());
+  WriteParam(m, p.extra_data_field());
   WriteParam(m, p.command_buffer_id());
   WriteParam(m, p.release_count());
 }
@@ -69,17 +70,19 @@ bool ParamTraits<gpu::SyncToken>::Read(const Message* m,
   bool verified_flush = false;
   gpu::CommandBufferNamespace namespace_id =
       gpu::CommandBufferNamespace::INVALID;
+  uint32_t extra_data_field = 0;
   uint64_t command_buffer_id = 0;
   uint64_t release_count = 0;
 
   if (!ReadParam(m, iter, &verified_flush) ||
       !ReadParam(m, iter, &namespace_id) ||
+      !ReadParam(m, iter, &extra_data_field) ||
       !ReadParam(m, iter, &command_buffer_id) ||
       !ReadParam(m, iter, &release_count)) {
     return false;
   }
 
-  p->Set(namespace_id, command_buffer_id, release_count);
+  p->Set(namespace_id, extra_data_field, command_buffer_id, release_count);
   if (p->HasData()) {
     if (!verified_flush)
       return false;
@@ -90,10 +93,10 @@ bool ParamTraits<gpu::SyncToken>::Read(const Message* m,
 }
 
 void ParamTraits<gpu::SyncToken>::Log(const param_type& p, std::string* l) {
-  *l +=
-      base::StringPrintf("[%d:%llX] %llu", static_cast<int>(p.namespace_id()),
-                         static_cast<unsigned long long>(p.command_buffer_id()),
-                         static_cast<unsigned long long>(p.release_count()));
+  *l += base::StringPrintf(
+      "[%d:%llX:%u] %llu", static_cast<int>(p.namespace_id()),
+      static_cast<unsigned long long>(p.command_buffer_id()),
+      p.extra_data_field(), static_cast<unsigned long long>(p.release_count()));
 }
 
 void ParamTraits<gpu::Mailbox>::Write(Message* m, const param_type& p) {