ipc: Update Message::FindNext to parse brokered attachments.

tools/ipc_fuzzer/message_lib/message_file_reader.cc

Index: tools/ipc_fuzzer/message_lib/message_file_reader.cc
diff --git a/tools/ipc_fuzzer/message_lib/message_file_reader.cc b/tools/ipc_fuzzer/message_lib/message_file_reader.cc
index e93c460b7e287dbfc3012b789db3b505f7b44f25..83a85c56b13e78fe8e847c185f099855384becb0 100644
--- a/tools/ipc_fuzzer/message_lib/message_file_reader.cc
+++ b/tools/ipc_fuzzer/message_lib/message_file_reader.cc
@@ -108,13 +108,14 @@ bool Reader::ReadMessages() {
   for (size_t i = 0; i < header_->message_count; ++i) {
     const char* begin = file_data_.begin();
     const char* end = file_data_.end();
-    const char* message_tail = IPC::Message::FindNext(begin, end);
-    if (!message_tail) {
+    IPC::Message::NextMessageInfo info = IPC::Message::FindNext(begin, end);

[Tom Sepez, 2015/09/01 18:01:54]

nit: the assignment may not be cheap; a copy of the entire attachment vector
will take place.

[erikchen, 2015/09/04 02:13:39]

I changed the signature of FindNext to take a NextMessageInfo* as an output
parameter.

+    if (!info.message_found) {
       LOG(ERROR) << "Failed to parse message.";
       return false;
     }
 
-    size_t msglen = message_tail - begin;
+    CHECK_EQ(info.message_end, info.pickle_end);
+    size_t msglen = info.message_end - begin;
     if (msglen > INT_MAX) {
       LOG(ERROR) << "Message too large.";
       return false;