Remove NOTIMPLEMENTED() from PlatformThread::SetThreadPriority() for posix.

tools/valgrind/tsan/suppressions.txt

 # There are a few kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 321 matching lines @@
   fun:*TOOLS_SANITY_TEST_CONCURRENT_THREAD::ThreadMain
 }
 
 {
   Benign race (or even a false positive) on atomics in ThreadCollisionWarner
   ThreadSanitizer:Race
   fun:base::subtle::NoBarrier_Store
   fun:base::ThreadCollisionWarner::Leave
 }
 
-{
-   bug_100026a
-   ThreadSanitizer:Race
-   ...
-   fun:std::*
-   ...
-   fun:logging::LogMessage::*LogMessage
-   fun:base::PlatformThread::SetThreadPriority
-   fun:base::SimpleThread::SetThreadPriority
-   fun:AudioDevice::Run
-}
-
-{
-   bug_100026b
-   ThreadSanitizer:Race
-   ...
-   fun:std::*
-   ...
-   fun:logging::LogMessage::*LogMessage
-   fun:base::PlatformThread::SetThreadPriority
-   fun:AudioDeviceThread::Thread::ThreadMain
-   ...
-}
-
 ############################
 # 2.2 Benign races in Chromium
 {
   bug_61179 [benign race on tracked_objects::Births]
   ThreadSanitizer:Race
   fun:tracked_objects::Births::*Birth*
 }
 
 {
   bug_62694 [benign races in Histogram in CookieMonster]
@@ skipping 475 matching lines @@
 }
 {
   bug_115540
   ThreadSanitizer:Race
   fun:base::Thread::message_loop
   fun:content::BrowserThreadImpl::PostTaskHelper
   fun:content::BrowserThread::PostTask
   fun:AudioRendererHost::OnCreated
   fun:media::AudioOutputController::DoCreate
 }