Linux Sandbox: split the GPU policies to their own file.

content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h

 // Copyright 2013 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.
 
-#ifndef CONTENT_COMMON_SANDBOX_BPF_BASE_POLICY_LINUX_H_
-#define CONTENT_COMMON_SANDBOX_BPF_BASE_POLICY_LINUX_H_
+#ifndef CONTENT_COMMON_SANDBOX_LINUX_SANDBOX_BPF_BASE_POLICY_LINUX_H_
+#define CONTENT_COMMON_SANDBOX_LINUX_SANDBOX_BPF_BASE_POLICY_LINUX_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "sandbox/linux/seccomp-bpf-helpers/baseline_policy.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf_policy.h"
 
 using sandbox::ErrorCode;
 using sandbox::SandboxBPF;
 
 namespace content {
 
 // The "baseline" BPF policy for content/. Any content/ seccomp-bpf policy
 // should inherit from it.
 // It implements the main SandboxBPFPolicy interface. Due to its nature
 // as a "kernel attack surface reduction" layer, it's implementation-defined.
 class SandboxBPFBasePolicy : public sandbox::SandboxBPFPolicy {
  public:
   SandboxBPFBasePolicy();
   virtual ~SandboxBPFBasePolicy();
 
   virtual ErrorCode EvaluateSyscall(SandboxBPF* sandbox_compiler,
                                     int system_call_number) const OVERRIDE;
+
+  // A policy can implement this hook to run code right before the policy
+  // is passed to the SandboxBPF class and the sandbox is engaged.
+  // If PreSandboxHook() returns true, the sandbox is guaranteed to be
+  // engaged afterwards.
+  // This will be used when enabling the sandbox though
+  // SandboxSeccompBPF::StartSandbox().
+  virtual bool PreSandboxHook();
+
   // Get the errno(3) to return for filesystem errors.
   static int GetFSDeniedErrno();
 
  private:
   // Compose the BaselinePolicy from sandbox/.
   scoped_ptr<sandbox::BaselinePolicy> baseline_policy_;
   DISALLOW_COPY_AND_ASSIGN(SandboxBPFBasePolicy);
 };
 
 }  // namespace content
 
-#endif  // CONTENT_COMMON_SANDBOX_BPF_BASE_POLICY_LINUX_H_
+#endif  // CONTENT_COMMON_SANDBOX_LINUX_SANDBOX_BPF_BASE_POLICY_LINUX_H_