Revert 68893 - Consider PlatformThread::Join() to be blocking IO....

chrome/browser/geolocation/geolocation_provider.cc

Index: chrome/browser/geolocation/geolocation_provider.cc
===================================================================
--- chrome/browser/geolocation/geolocation_provider.cc	(revision 68914)
+++ chrome/browser/geolocation/geolocation_provider.cc	(working copy)
@@ -5,7 +5,6 @@
 #include "chrome/browser/geolocation/geolocation_provider.h"
 
 #include "base/singleton.h"
-#include "base/thread_restrictions.h"
 #include "chrome/browser/geolocation/location_arbitrator.h"
 
 // This class is guaranteed to outlive its internal thread, so ref counting
@@ -48,10 +47,6 @@
 void GeolocationProvider::OnObserversChanged() {
   DCHECK(OnClientThread());
   if (observers_.empty()) {
-    // http://crbug.com/66077: This is a bug.  The geolocation thread may
-    // transitively (via other threads it joins) block on long-running tasks /
-    // IO.
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
     Stop();
   } else {
     if (!IsRunning()) {