NaCl: enable meta-based validation for shared libraries.

chrome/common/nacl_messages.h

Index: chrome/common/nacl_messages.h
diff --git a/chrome/common/nacl_messages.h b/chrome/common/nacl_messages.h
index acafe7ecccd89d9b950a2bceb95b1ba98b2e7160..5d223ed1af8a4d4e88c8b11ebc5bd2f805a8e19e 100644
--- a/chrome/common/nacl_messages.h
+++ b/chrome/common/nacl_messages.h
@@ -9,6 +9,7 @@
 #include "chrome/common/nacl_types.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_platform_file.h"
 
 #define IPC_MESSAGE_START NaClMsgStart
 
@@ -78,6 +79,15 @@ IPC_SYNC_MESSAGE_CONTROL1_1(NaClProcessMsg_QueryKnownToValidate,
 IPC_MESSAGE_CONTROL1(NaClProcessMsg_SetKnownToValidate,
                      std::string /* A validation signature */)
 
+// Used by the NaCl process to aquire trusted information about a file directly

[Mark Seaborn, 2013/05/24 20:21:58]

"acquire"

[Nick Bray (chromium), 2013/05/24 21:35:24]

Done.

+// from the browser, including the file's path as well as a fresh version of the
+// file handle.
+IPC_SYNC_MESSAGE_CONTROL2_2(NaClProcessMsg_ResolveFileToken,

[Mark Seaborn, 2013/05/24 20:21:58]

"Resolve" is vague.  How about "OpenFileFromToken" or "OpenFileGivenToken"?

(I know you already used the term "Resolve" in the NaCl code, but I still think
it would be better to use "Open" here.)

[Nick Bray (chromium), 2013/05/24 21:35:24]

Opening is only part of the elephant.  I don't think "Open" is the right verb. 
"Given" is also an awkward way to resolve the resulting ambiguity.  Leaving as
is.

+                            uint64, /* file_token_lo */
+                            uint64, /* file_token_hi */
+                            IPC::PlatformFileForTransit, /* fd */
+                            base::FilePath /* Path opened to get fd */)
+
 // Notify the browser process that the server side of the PPAPI channel was
 // created successfully.
 IPC_MESSAGE_CONTROL1(NaClProcessHostMsg_PpapiChannelCreated,