Decrease the verbosity of the -ftime-trace option And move the relevant information in the doc.

[sylvestre.ledru]

Summary

Currently, building a large software like Firefox shows
'Use chrome://tracing or Speedscope App (https://www.speedscope.app) for flamegraph visualization'
for each file.

[anton-afanasyev]

I believe it's better solution, LGTM.

[sylvestre.ledru]

thanks :)

cfe/trunk/docs/ClangCommandLineReference.rst

 Perform ThinLTO importing using provided function summary index
 
 .. option:: -fthreadsafe-statics, -fno-threadsafe-statics
 
 .. option:: -ftime-report
 
 .. option:: -ftime-trace
 
-Turn on time profiler
+Turn on time profiler. Results can be analyzed with chrome://tracing or
+`Speedscope App <https://www.speedscope.app>`_ for flamegraph visualization
 
 .. option:: -ftime-trace-granularity=<arg>
 
 Minimum time granularity (in microseconds) traced by time profiler
 
 .. option:: -ftls-model=<arg>
 
 .. option:: -ftrap-function=<arg>

cfe/trunk/tools/driver/cc1_main.cpp

auto profilerOutput =
                                 /*useTemporary=*/false);
 
     llvm::timeTraceProfilerWrite(*profilerOutput);
     // FIXME(ibiryukov): make profilerOutput flush in destructor instead.
     profilerOutput->flush();
     llvm::timeTraceProfilerCleanup();
 
     llvm::errs() << "Time trace json-file dumped to " << Path.str() << "\n";
-    llvm::errs()
-        << "Use chrome://tracing or Speedscope App "
-           "(https://www.speedscope.app) for flamegraph visualization\n";
   }
 
   // Our error handler depends on the Diagnostics object, which we're
   // potentially about to delete. Uninstall the handler now so that any
   // later errors use the default handling behavior instead.
   llvm::remove_fatal_error_handler();
 
   // When running with -disable-free, don't do any destruction or shutdown.
   if (Clang->getFrontendOpts().DisableFree) {
     llvm::BuryPointer(std::move(Clang));
     return !Success;
   }
 
   return !Success;
 }