Linux GPU sandbox: only allocate broker policy in the broker.

content/common/sandbox_linux/bpf_gpu_policy_linux.h

Index: content/common/sandbox_linux/bpf_gpu_policy_linux.h
diff --git a/content/common/sandbox_linux/bpf_gpu_policy_linux.h b/content/common/sandbox_linux/bpf_gpu_policy_linux.h
index 496a39e65550799e5ae91461157770c96f3e25c7..6da4d04d30f9b2c95b89115c35535155acd48cf5 100644
--- a/content/common/sandbox_linux/bpf_gpu_policy_linux.h
+++ b/content/common/sandbox_linux/bpf_gpu_policy_linux.h
@@ -29,13 +29,13 @@ class GpuProcessPolicy : public SandboxBPFBasePolicy {
 
  protected:
   // Start a broker process to handle open() inside the sandbox.
-  // |broker_sandboxer_callback| is a callback that will enable a suitable
-  // sandbox for the broker process itself.
+  // |broker_sandboxer_allocator| is a function pointer which can allocate a
+  // suitable sandbox policy for the broker process itself.
   // |read_whitelist_extra| and |write_whitelist_extra| are lists of file
   // names that should be whitelisted by the broker process, in addition to
   // the basic ones.
   void InitGpuBrokerProcess(
-      const base::Callback<bool(void)>& broker_sandboxer_callback,
+      sandbox::SandboxBPFPolicy* (*broker_sandboxer_allocator)(void),

[Jorge Lucangeli Obes, 2014/04/28 23:43:53]

It was nice to have base::Callback's instead of function pointers, they're
definitely easier to read. But I guess this way you can just pass the static
method directly.

[jln (very slow on Chromium), 2014/04/28 23:53:18]

We could still make it a CallBack if we really wanted to, but the CallBack
taking a CallBack as a parameter that goes across fork() seemed too complicated
to follow.

       const std::vector<std::string>& read_whitelist_extra,
       const std::vector<std::string>& write_whitelist_extra);