Added SyncToken command buffer trait to help with IPC messages.

content/common/gpu/gpu_command_buffer_stub.cc

Index: content/common/gpu/gpu_command_buffer_stub.cc
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 381f354a9446a4759775e4cd9e579f48edb4e3bf..60307394f3f5cd3675feb7e1937d5ffd81d7dc40 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -24,8 +24,8 @@
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/common/constants.h"
-#include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/common/sync_token.h"
 #include "gpu/command_buffer/service/gl_context_virtual.h"
 #include "gpu/command_buffer/service/gl_state_restorer_impl.h"
 #include "gpu/command_buffer/service/image_factory.h"
@@ -940,8 +940,9 @@ void GpuCommandBufferStub::OnRetireSyncPoint(uint32 sync_point) {
     // We can simply use the global sync point number as the release count with
     // 0 for the command buffer ID (under normal circumstances 0 is invalid so
     // will not be used) until the old sync points are replaced.
-    gpu::gles2::SyncToken sync_token = {gpu::CommandBufferNamespace::GPU_IO, 0,
-                                        sync_point};
+    gpu::SyncToken sync_token(gpu::CommandBufferNamespace::GPU_IO,
+                              0,
+                              sync_point);
     mailbox_manager->PushTextureUpdates(sync_token);
   }
 
@@ -998,8 +999,7 @@ void GpuCommandBufferStub::PullTextureUpdates(
   gpu::gles2::MailboxManager* mailbox_manager =
       context_group_->mailbox_manager();
   if (mailbox_manager->UsesSync() && MakeCurrent()) {
-    gpu::gles2::SyncToken sync_token = {namespace_id, command_buffer_id,
-                                        release};
+    gpu::SyncToken sync_token(namespace_id, command_buffer_id, release);
     mailbox_manager->PullTextureUpdates(sync_token);
   }
 }
@@ -1045,8 +1045,9 @@ void GpuCommandBufferStub::OnFenceSyncRelease(uint64_t release) {
   gpu::gles2::MailboxManager* mailbox_manager =
       context_group_->mailbox_manager();
   if (mailbox_manager->UsesSync() && MakeCurrent()) {
-    gpu::gles2::SyncToken sync_token = {gpu::CommandBufferNamespace::GPU_IO,
-                                        command_buffer_id_, release};
+    gpu::SyncToken sync_token(gpu::CommandBufferNamespace::GPU_IO,
+                              command_buffer_id_,
+                              release);
     mailbox_manager->PushTextureUpdates(sync_token);
   }