Bug 1521608 - Tweak MOZ_PROFILER_HELP log message. r=canaltinova

Differential Revision: https://phabricator.services.mozilla.com/D17160

--HG--
extra : moz-landing-system : lando

tools/profiler/core/platform.cpp

@@ -783,7 +783,7 @@ class ActivePS {
   // The maximum number of entries in mBuffer.
   const uint32_t mCapacity;
 
-  // The maximum duration of entries in mBuffer.
+  // The maximum duration of entries in mBuffer, in seconds.
   const Maybe<double> mDuration;
 
   // The interval between samples, measured in milliseconds.
@@ -2078,11 +2078,12 @@ static void PrintUsageThenExit(int aExitCode) {
       "  If unset, the platform default is used.\n"
       "\n"
       "  MOZ_PROFILER_STARTUP_DURATION=<1..>\n"
-      "  If MOZ_PROFILER_STARTUP is set, specifies the duration of entries in\n"
-      "  the profiler's circular buffer when the profiler is first started.\n"
-      "  If unset, duration of the entries will be restricted by.\n"
-      "  MOZ_PROFILER_STARTUP_ENTRIES or its default value instead of a time "
-      "duration."
+      "  If MOZ_PROFILER_STARTUP is set, specifies the maximum life time of\n"
+      "  entries in the the profiler's circular buffer when the profiler is\n"
+      "  first started, in seconds.\n"
+      "  If unset, the life time of the entries will only be restricted by\n"
+      "  MOZ_PROFILER_STARTUP_ENTRIES (or its default value), and no\n"
+      "  additional time duration restriction will be applied.\n"
       "\n"
       "  MOZ_PROFILER_STARTUP_INTERVAL=<1..1000>\n"
       "  If MOZ_PROFILER_STARTUP is set, specifies the sample interval,\n"
@@ -2102,10 +2103,9 @@ static void PrintUsageThenExit(int aExitCode) {
       "\n"
       "  MOZ_PROFILER_STARTUP_FILTERS=<Filters>\n"
       "  If MOZ_PROFILER_STARTUP is set, specifies the thread filters, as a\n"
-      "  comma-separated list of strings. A given thread will be sampled if "
-      "any\n"
-      "  of the filters is a case-insensitive substring of the thread name.\n"
-      "  If unset, a default is used.\n"
+      "  comma-separated list of strings. A given thread will be sampled if\n"
+      "  any of the filters is a case-insensitive substring of the thread\n"
+      "  name. If unset, a default is used.\n"
       "\n"
       "  MOZ_PROFILER_SHUTDOWN\n"
       "  If set, the profiler saves a profile to the named file on shutdown.\n"