Bug 1598531 - Output Base Profiler logging to stderr, so it is correctly sync'd with MOZ_LOG - r=gregtatum

This is especially useful when debugging both Base Profiler and Gecko Profiler,
so that their messages are correctly sequenced.

Differential Revision: https://phabricator.services.mozilla.com/D54447

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

mozglue/baseprofiler/core/platform.h

@@ -46,34 +46,34 @@ bool BaseProfilerLogTest(int aLevelToTest);
 // These are for MOZ_BASE_PROFILER_LOGGING and above. It's the default logging
 // level for the profiler, and should be used sparingly.
 #define LOG_TEST BaseProfilerLogTest(3)
-#define LOG(arg, ...)                                              \
-  do {                                                             \
-    if (LOG_TEST) {                                                \
-      printf("[I %d/%d] " arg "\n", profiler_current_process_id(), \
-             profiler_current_thread_id(), ##__VA_ARGS__);         \
-    }                                                              \
+#define LOG(arg, ...)                                                       \
+  do {                                                                      \
+    if (LOG_TEST) {                                                         \
+      fprintf(stderr, "[I %d/%d] " arg "\n", profiler_current_process_id(), \
+              profiler_current_thread_id(), ##__VA_ARGS__);                 \
+    }                                                                       \
   } while (0)
 
 // These are for MOZ_BASE_PROFILER_DEBUG_LOGGING. It should be used for logging
 // that is somewhat more verbose than LOG.
 #define DEBUG_LOG_TEST BaseProfilerLogTest(4)
-#define DEBUG_LOG(arg, ...)                                        \
-  do {                                                             \
-    if (DEBUG_LOG_TEST) {                                          \
-      printf("[D %d/%d] " arg "\n", profiler_current_process_id(), \
-             profiler_current_thread_id(), ##__VA_ARGS__);         \
-    }                                                              \
+#define DEBUG_LOG(arg, ...)                                                 \
+  do {                                                                      \
+    if (DEBUG_LOG_TEST) {                                                   \
+      fprintf(stderr, "[D %d/%d] " arg "\n", profiler_current_process_id(), \
+              profiler_current_thread_id(), ##__VA_ARGS__);                 \
+    }                                                                       \
   } while (0)
 
 // These are for MOZ_BASE_PROFILER_VERBOSE_LOGGING. It should be used for
 // logging that is somewhat more verbose than DEBUG_LOG.
 #define VERBOSE_LOG_TEST BaseProfilerLogTest(5)
-#define VERBOSE_LOG(arg, ...)                                      \
-  do {                                                             \
-    if (VERBOSE_LOG_TEST) {                                        \
-      printf("[V %d/%d] " arg "\n", profiler_current_process_id(), \
-             profiler_current_thread_id(), ##__VA_ARGS__);         \
-    }                                                              \
+#define VERBOSE_LOG(arg, ...)                                               \
+  do {                                                                      \
+    if (VERBOSE_LOG_TEST) {                                                 \
+      fprintf(stderr, "[V %d/%d] " arg "\n", profiler_current_process_id(), \
+              profiler_current_thread_id(), ##__VA_ARGS__);                 \
+    }                                                                       \
   } while (0)
 
 namespace mozilla {