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

cc/trees/layer_tree_host_perftest.cc

Index: cc/trees/layer_tree_host_perftest.cc
diff --git a/cc/trees/layer_tree_host_perftest.cc b/cc/trees/layer_tree_host_perftest.cc
index 556ad63085cc97595e1411cab93813986fb8b5aa..fa546b2936f26bd983903c053e4354411a9abf90 100644
--- a/cc/trees/layer_tree_host_perftest.cc
+++ b/cc/trees/layer_tree_host_perftest.cc
@@ -297,7 +297,8 @@ class BrowserCompositorInvalidateLayerTreePerfTest
     scoped_ptr<SingleReleaseCallback> callback = SingleReleaseCallback::Create(
         base::Bind(&EmptyReleaseCallback));
 
-    gpu::SyncToken next_sync_token(gpu::CommandBufferNamespace::GPU_IO, 0, 1,
+    gpu::SyncToken next_sync_token(gpu::CommandBufferNamespace::GPU_IO, 0,
+                                   gpu::CommandBufferId::FromUnsafeValue(1),
                                    next_fence_sync_);
     next_sync_token.SetVerifyFlush();
     TextureMailbox mailbox(gpu_mailbox, next_sync_token, GL_TEXTURE_2D);