Rewrite all BPF policies to use DSL API

content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h

Index: content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h
diff --git a/content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h b/content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h
index 6d9d83f4fa1f81827085e87df28f05a3fd9184cb..c00484c40931cfd3ef3e7c20896fe3efa8f20d1d 100644
--- a/content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h
+++ b/content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h
@@ -19,13 +19,14 @@ namespace content {
 // 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 {
+class SandboxBPFBasePolicy : public sandbox::bpf_dsl::SandboxBPFPolicyDSL {
  public:
   SandboxBPFBasePolicy();
   virtual ~SandboxBPFBasePolicy();
 
-  virtual ErrorCode EvaluateSyscall(SandboxBPF* sandbox_compiler,
-                                    int system_call_number) const OVERRIDE;
+  using sandbox::bpf_dsl::SandboxBPFPolicyDSL::EvaluateSyscall;
+  virtual sandbox::bpf_dsl::ResultExpr EvaluateSyscall(
+      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.