Introducing gpu::CommandBufferId as a distinct, IdType<...>-based type.

gpu/ipc/gpu_command_buffer_traits.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/ipc/gpu_command_buffer_traits.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
+#include "gpu/command_buffer/common/command_buffer_id.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "gpu/command_buffer/common/sync_token.h"
 #include "gpu/command_buffer/common/value_state.h"
 
 // Generate param traits size methods.
 #include "ipc/param_traits_size_macros.h"
 namespace IPC {
 #include "gpu/ipc/gpu_command_buffer_traits_multi.h"
 }  // namespace IPC
 
@@ skipping 68 matching lines @@
   WriteParam(m, p.command_buffer_id());
   WriteParam(m, p.release_count());
 }
 
 bool ParamTraits<gpu::SyncToken>::Read(const base::Pickle* m,
                                        base::PickleIterator* iter,
                                        param_type* p) {
   bool verified_flush = false;
   gpu::CommandBufferNamespace namespace_id =
       gpu::CommandBufferNamespace::INVALID;
-  uint64_t command_buffer_id = 0;
+  gpu::CommandBufferId command_buffer_id;
   uint64_t release_count = 0;
 
   if (!ReadParam(m, iter, &verified_flush) ||
       !ReadParam(m, iter, &namespace_id) ||
       !ReadParam(m, iter, &command_buffer_id) ||
       !ReadParam(m, iter, &release_count)) {
     return false;
   }
 
   p->Set(namespace_id, 0, command_buffer_id, release_count);
   if (p->HasData()) {
     if (!verified_flush)
       return false;
     p->SetVerifyFlush();
   }
 
   return true;
 }
 
 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] %llu", static_cast<int>(p.namespace_id()),

[dcheng, 2016/02/12 19:23:17]

How about:

*l += base::StringPrintf("[%d:" PRIu64 "] " PRIu64,
    static_cast<p.namespace_id()),
    p.command_buffer_id().GetUnsafeValue(), p.release_count());

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Done - thanks for catching this.  Can you please double-check what I did?
- I switched to PRIX64 and PRIu64 to avoid %llu and static casts to unsigned
long long.  The last 2 arguments are both uint64_t.
- I also wanted to get rid of the static_cast on the first placeholder argument.
 The cast is not needed, because argv will pass them as int.  For consistency I
switched from "%d" to |"%" PRId8|.

+      static_cast<unsigned long long>(p.command_buffer_id().GetUnsafeValue()),
+      static_cast<unsigned long long>(p.release_count()));
 }
 
 void ParamTraits<gpu::Mailbox>::GetSize(base::PickleSizer* s,
                                         const param_type& p) {
   s->AddBytes(sizeof(p.name));
 }
 
 void ParamTraits<gpu::Mailbox>::Write(base::Pickle* m, const param_type& p) {
   m->WriteBytes(p.name, sizeof(p.name));
 }
@@ skipping 69 matching lines @@
   l->append("<ValueState (");
   for (int value : p.int_value)
     *l += base::StringPrintf("%i ", value);
   l->append(" int values ");
   for (float value : p.float_value)
     *l += base::StringPrintf("%f ", value);
   l->append(" float values)>");
 }
 
 }  // namespace IPC