Make chrome_elf use thunks instead of function pointers.

sandbox/win/src/service_resolver.h

Index: sandbox/win/src/service_resolver.h
diff --git a/sandbox/win/src/service_resolver.h b/sandbox/win/src/service_resolver.h
index 00896922049ad45b569a111f97384cb97f57782b..20486c99d6a3ef72647fde2e83ab46a62dd76171 100644
--- a/sandbox/win/src/service_resolver.h
+++ b/sandbox/win/src/service_resolver.h
@@ -46,6 +46,15 @@ class ServiceResolverThunk : public ResolverThunk {
   // Call this to set up ntdll_base_ which will allow for local patches.
   virtual void AllowLocalPatches();
 
+  // Verifies that the function specified by |target_name| in |target_module| is
+  // a service and copies the data from that function into |thunk_storage|. If
+  // |storage_bytes| is too small, then the method fails.
+  virtual NTSTATUS CopyThunk(const void* target_module,
+                             const char* target_name,
+                             BYTE* thunk_storage,
+                             size_t storage_bytes,
+                             size_t* storage_used);
+
  protected:
   // The unit test will use this member to allow local patch on a buffer.
   HMODULE ntdll_base_;