Remove BrowserThread::UnsafeGetBrowserThread, add UnsafeGetMessageLoopForThread.

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index cf3861ae747adec91429cbaac386b0cc6ea53deb..4d13782e0c49872ed7e681381c05e7ca9c161509 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -291,6 +291,10 @@ void BrowserProcessImpl::PostStopThread(BrowserThread::ID thread_id) {
       // Reset associated state right after actual thread is stopped,
       // as io_thread_.global_ cleanup happens in CleanUp on the IO
       // thread, i.e. as the thread exits its message loop.
+      //
+      // This is important also because in various places, the
+      // IOThread object being NULL is considered synonymous with the
+      // IO thread having stopped.
       io_thread_.reset();
       break;
     default:
@@ -414,16 +418,6 @@ IOThread* BrowserProcessImpl::io_thread() {
   return io_thread_.get();
 }
 
-base::Thread* BrowserProcessImpl::file_thread() {
-  DCHECK(CalledOnValidThread());
-  return BrowserThread::UnsafeGetBrowserThread(BrowserThread::FILE);
-}
-
-base::Thread* BrowserProcessImpl::db_thread() {
-  DCHECK(CalledOnValidThread());
-  return BrowserThread::UnsafeGetBrowserThread(BrowserThread::DB);
-}
-
 WatchDogThread* BrowserProcessImpl::watchdog_thread() {
   DCHECK(CalledOnValidThread());
   if (!created_watchdog_thread_)
@@ -432,13 +426,6 @@ WatchDogThread* BrowserProcessImpl::watchdog_thread() {
   return watchdog_thread_.get();
 }
 
-#if defined(OS_CHROMEOS)
-base::Thread* BrowserProcessImpl::web_socket_proxy_thread() {
-  DCHECK(CalledOnValidThread());
-  return BrowserThread::UnsafeGetBrowserThread(BrowserThread::WEB_SOCKET_PROXY);
-}
-#endif
-
 ProfileManager* BrowserProcessImpl::profile_manager() {
   DCHECK(CalledOnValidThread());
   if (!created_profile_manager_)