RFC: Add an interface for having the browser open a pnacl support file

chrome/renderer/chrome_ppapi_interfaces.cc

Index: chrome/renderer/chrome_ppapi_interfaces.cc
diff --git a/chrome/renderer/chrome_ppapi_interfaces.cc b/chrome/renderer/chrome_ppapi_interfaces.cc
index 517dbcfdbdabfd3e3d9e962b772dd9122574a039..ac11993107f92531c5a9192f132359309aca214e 100644
--- a/chrome/renderer/chrome_ppapi_interfaces.cc
+++ b/chrome/renderer/chrome_ppapi_interfaces.cc
@@ -69,6 +69,33 @@ int UrandomFD(void) {
 #endif
 }
 
+int GetReadonlyPnaclFD(const char* filename) {
+  nacl::FileDescriptor out_fd;
+  if (!RenderThread::Get()->Send(
+      new ChromeViewHostMsg_GetReadonlyPnaclFD(
+          std::string(filename),
+          &out_fd))) {
+    return -1;
+  }
+
+  // TODO(jvoung): Should nacl::FileDescriptor handle this?
+  // Should we leave the HANDLE as a HANDLE for now?
+#if defined(OS_WIN)
+  HANDLE handle = nacl::ToNativeHandle(out_fd);
+  int posix_desc = _open_osfhandle(handle, _O_RDONLY | _O_BINARY);
+  if (posix_desc == -1) {
+    // Close the Windows HANDLE if it can't be converted.
+    CloseHandle(handle);
+    return -1;
+  }
+  return posix_desc;
+#elif defined(OS_POSIX)
+  return nacl::ToNativeHandle(out_fd);
+#else
+#error "GetReadonlyPnaclFD: Don't know how to convert FileDescriptor to native."
+#endif
+}
+
 bool Are3DInterfacesDisabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisable3DAPIs);
 }
@@ -83,6 +110,7 @@ const PPB_NaCl_Private ppb_nacl = {
   &UrandomFD,
   &Are3DInterfacesDisabled,
   &EnableBackgroundSelLdrLaunch,
+  &GetReadonlyPnaclFD
 };
 
 class PPB_NaCl_Impl {