To reproduce:
* Sync to Chromium commit 0877ce62e907e9a76083121c29ce4c7d31f2949f (p463777) and build net_unittests.  (I can't imagine the Chromium commit matters very much, except possibly for the line number for the breakpoint below.)

* Build lldb from tree tip.  The commits I used (via "git pull" today) were:
** llvm: d8dec6c86f982f17e9d06aff22f680e1fe3a8784
** clang: dbf1b8007c7d43ca8c802b277a75785f1c0ed3ae
** 449d2091fc0842092b317d3db3c72a2b6fbf1a6e

Log showing problems converting state value.  If these show multiple problems (or pilot error for some problems) please focus on the first failure, as what I'm trying to do is eventually create a function via expression -- \n <fndef> to convert from state values to strings for debug logging.

The problem may not actually be the private class, that was just my best guess when the top level refused to recognize 'Transacation' (which is defined in its own .h file, but its relationship with HttpCache is specified in the http_cache.h file via a "class Transaction" after the private: label).

rdsmith-macbookpro:../chrome/src [master]  $ lldb out/Default/net_unittests
lldb out/Default/net_unittests
(lldb) target create "out/Default/net_unittests"
Current executable set to 'out/Default/net_unittests' (x86_64).
(lldb) p net::HttpCache::Transaction::STATE_NONE
p net::HttpCache::Transaction::STATE_NONE
error: 'Transaction' is not a class, namespace, or enumeration
(lldb) break set -f http_cache_transaction.cc -l 710
break set -f http_cache_transaction.cc -l 710
Breakpoint 1: where = libnet.dylib`net::HttpCache::Transaction::DoLoop(int) + 570 at http_cache_transaction.cc:710, address = 0x0000000000637afa
(lldb) run --gtest_filter=HttpCache.RangeGET_NoStrongValidators
run --gtest_filter=HttpCache.RangeGET_NoStrongValidators
Process 26803 launched: '/Users/rdsmith/Sandboxen/chrome/src/out/Default/net_unittests' (x86_64)
Debugger detected, switching to single process mode.
Pass --test-launcher-debug-launcher to debug the launcher itself.
Detected presence of a debugger, running without test timeouts.
Note: Google Test filter = HttpCache.RangeGET_NoStrongValidators
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from HttpCache
[ RUN      ] HttpCache.RangeGET_NoStrongValidators
Process 26803 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x00000001092dfafa libnet.dylib`net::HttpCache::Transaction::DoLoop(this=0x000000010e02ee00, result=0) at http_cache_transaction.cc:710
   707 	  int rv = result;
   708 	  do {
   709 	    State state = next_state_;
-> 710 	    next_state_ = STATE_UNSET;
    	                ^
   711 	    base::AutoReset<bool> scoped_in_do_loop(&in_do_loop_, true);
   712 	
   713 	    switch (state) {
(lldb) p net::HttpCache::Transaction::STATE_NONE
p net::HttpCache::Transaction::STATE_NONE
error: reference to 'HttpCache' is ambiguous
candidate found by name lookup is 'net::HttpCache'
candidate found by name lookup is 'net::HttpCache'
(lldb) p HttpCache::Transaction::STATE_NONE
p HttpCache::Transaction::STATE_NONE
error: 'Transaction' is not a class, namespace, or enumeration
error: reference to 'Transaction' is ambiguous
candidate found by name lookup is 'Transaction'
candidate found by name lookup is 'Transaction'
(lldb) p Transaction::STATE_NONE
p Transaction::STATE_NONE
error: reference to 'Transaction' is ambiguous
candidate found by name lookup is 'Transaction'
candidate found by name lookup is 'Transaction'
(lldb) p STATE_NONE
p STATE_NONE
(int) $0 = 1
(lldb)