Linux sandbox: cleanup sandbox-bpf naming.

sandbox/linux/seccomp-bpf-helpers/baseline_policy.h

Index: sandbox/linux/seccomp-bpf-helpers/baseline_policy.h
diff --git a/sandbox/linux/seccomp-bpf-helpers/baseline_policy.h b/sandbox/linux/seccomp-bpf-helpers/baseline_policy.h
index 88dd9dc40b41133f84ef6e42383f6c21211d9d72..9633fa59d43713427ece6f785a614cc7145dcd18 100644
--- a/sandbox/linux/seccomp-bpf-helpers/baseline_policy.h
+++ b/sandbox/linux/seccomp-bpf-helpers/baseline_policy.h
@@ -8,17 +8,11 @@
 #include "sandbox/linux/seccomp-bpf/errorcode.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf_policy.h"
 
-namespace playground2 {
-class Sandbox;
-class SandboxBpfPolicy;
-}
-
-using playground2::ErrorCode;
-using playground2::Sandbox;
-using playground2::SandboxBpfPolicy;
-
 namespace sandbox {
 
+class SandboxBPF;
+class SandboxBpfPolicy;
+
 // This is a helper to build seccomp-bpf policies, i.e. policies for a sandbox
 // that reduces the Linux kernel's attack surface. Given its nature, it doesn't
 // have a clear semantics and is mostly "implementation-defined".
@@ -36,11 +30,11 @@ class BaselinePolicy : public SandboxBpfPolicy {
   explicit BaselinePolicy(int fs_denied_errno);
   virtual ~BaselinePolicy();
 
-  virtual ErrorCode EvaluateSyscall(Sandbox* sandbox_compiler,
+  virtual ErrorCode EvaluateSyscall(SandboxBPF* sandbox_compiler,
                                     int system_call_number) const OVERRIDE;
   // TODO(jln): remove once NaCl uses the new policy format. Do not use in new
   // code. This is the same as EvaluateSyscall. |aux| must be NULL.
-  static ErrorCode BaselinePolicyDeprecated(Sandbox* sandbox,
+  static ErrorCode BaselinePolicyDeprecated(SandboxBPF* sandbox,
                                             int sysno,
                                             void* aux);