Add sandbox support for Windows process mitigations

sandbox/win/src/sandbox_policy.h

Index: sandbox/win/src/sandbox_policy.h
===================================================================
--- sandbox/win/src/sandbox_policy.h	(revision 154997)
+++ sandbox/win/src/sandbox_policy.h	(working copy)
@@ -164,6 +164,26 @@
   // Sets a capability to be enabled for the sandboxed process' AppContainer.
   virtual ResultCode SetCapability(const wchar_t* sid) = 0;
 
+  // Sets the mitigation flags used when starting the process. These flags are
+  // defined in the PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY attribute for the
+  // UpdateProcThreadAttribute function. Flags that are invalid for the
+  // target OS will be silently ignored.
+  virtual ResultCode SetProcessMitigations(uint64 flags) = 0;
+

[cpu_(ooo_6.6-7.5), 2012/09/06 19:46:15]

The flags are our flags but the comment  can take the user to the msdn ones by
googling PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY. 

But more generally, the mitigation flags need to be here or in a file that is
more 'interfacy' than process_mitigations.h. So what I propose is either:

1) move the flags here
2) create a mitigations header like security_level.h

[jschuh, 2012/09/07 01:14:22]

Done.

+  // Returns the currently set mitigation policy.
+  virtual uint64 GetProcessMitigations() = 0;
+
+  // Sets the process mitigation flags. These flags will not take effect
+  // before you call LowerToken.  These flags are are defined in the
+  // PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY attribute for the
+  // UpdateProcThreadAttribute function. Flags that are invalid for the
+  // target OS will be silently ignored. Flags that are invalid after process
+  // startup will return SBOX_ERROR_BAD_PARAMS.
+  virtual ResultCode SetDelayedProcessMitigations(uint64 flags) = 0;
+
+  // Returns the currently set delayed mitigation policy.
+  virtual uint64 GetDelayedProcessMitigations() = 0;
+
   // Sets the interceptions to operate in strict mode. By default, interceptions
   // are performed in "relaxed" mode, where if something inside NTDLL.DLL is
   // already patched we attempt to intercept it anyway. Setting interceptions