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

mojo/gles2/command_buffer_client_impl.cc

Index: mojo/gles2/command_buffer_client_impl.cc
diff --git a/mojo/gles2/command_buffer_client_impl.cc b/mojo/gles2/command_buffer_client_impl.cc
index 5706af0d5d5e497d45c1497e8bf92fa41d5b04f0..3c19ea7b7191720c1d6af6156402a1dfa4cba0d1 100644
--- a/mojo/gles2/command_buffer_client_impl.cc
+++ b/mojo/gles2/command_buffer_client_impl.cc
@@ -66,7 +66,7 @@ CommandBufferClientImpl::CommandBufferClientImpl(
     : delegate_(delegate),
       attribs_(attribs),
       observer_binding_(this),
-      command_buffer_id_(0),
+      command_buffer_id_(),
       shared_state_(NULL),
       last_put_offset_(-1),
       next_transfer_buffer_id_(0),
@@ -116,7 +116,8 @@ bool CommandBufferClientImpl::Initialize() {
   }
 
   DCHECK_EQ(gpu::CommandBufferNamespace::MOJO, info->command_buffer_namespace);
-  command_buffer_id_ = info->command_buffer_id;
+  command_buffer_id_ =
+      gpu::CommandBufferId::FromUnsafeValue(info->command_buffer_id);
   capabilities_ = info->capabilities.To<gpu::Capabilities>();
   return true;
 }
@@ -323,7 +324,7 @@ gpu::CommandBufferNamespace CommandBufferClientImpl::GetNamespaceID() const {
   return gpu::CommandBufferNamespace::MOJO;
 }
 
-uint64_t CommandBufferClientImpl::GetCommandBufferID() const {
+gpu::CommandBufferId CommandBufferClientImpl::GetCommandBufferID() const {
   return command_buffer_id_;
 }