Cleanup base profiler initialization code.

Given that TLS slot can't fail to initialize, remove bool return values
from initialization functions that actually can't fail.

Based off of vadimt@'s CL here:
https://codereview.chromium.org/1124493002/

BUG=456354

Review URL: https://codereview.chromium.org/1128653002

Cr-Commit-Position: refs/heads/master@{#328774}
diff --git a/base/tracked_objects.h b/base/tracked_objects.h
index efa8859..8f83794 100644
--- a/base/tracked_objects.h
+++ b/base/tracked_objects.h
@@ -499,14 +499,13 @@
   const std::string& thread_name() const { return thread_name_; }
 
   // Initializes all statics if needed (this initialization call should be made
-  // while we are single threaded).  Returns false if unable to initialize.
-  static bool Initialize();
+  // while we are single threaded).
+  static void Initialize();
 
   // Sets internal status_.
   // If |status| is false, then status_ is set to DEACTIVATED.
   // If |status| is true, then status_ is set to PROFILING_ACTIVE.
-  // If it fails to initialize the TLS slot, this function will return false.
-  static bool InitializeAndSetTrackingStatus(Status status);
+  static void InitializeAndSetTrackingStatus(Status status);
 
   static Status status();