Try again to use a C++11 feature in DM as a canary.

dm/DM.cpp

 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
 #include "OverwriteLine.h"
 #include "ProcStats.h"
 #include "SkBBHFactory.h"
 #include "SkChecksum.h"
 #include "SkCommonFlags.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
@@ skipping 37 matching lines @@
 }
 
 static int32_t gPending = 0;  // Atomic.
 
 static void done(double ms,
                  ImplicitString config, ImplicitString src, ImplicitString name,
                  ImplicitString log) {
     if (!log.isEmpty()) {
         log.prepend("\n");
     }
-    int32_t pending = sk_atomic_dec(&gPending)-1;
+    auto pending = sk_atomic_dec(&gPending)-1;
     SkDebugf("%s(%4dMB %5d) %s\t%s %s %s%s", FLAGS_verbose ? "\n" : kSkOverwriteLine
                                            , sk_tools::getMaxResidentSetSizeMB()
                                            , pending
                                            , HumanizeMs(ms).c_str()
                                            , config.c_str()
                                            , src.c_str()
                                            , name.c_str()
                                            , log.c_str());
     // We write our dm.json file every once in a while in case we crash.
     // Notice this also handles the final dm.json when pending == 0.
@@ skipping 488 matching lines @@
     }
     return 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif