Move Indexed DB from dedicated thread to task scheduler

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index aa8fa9b89f30b8b5346cb10ad3302ffa60dbb203..ea5ed063a23bf2a6fa308f9cdb395428405709e4 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -363,12 +363,6 @@ NOINLINE void ResetThread_IO(std::unique_ptr<BrowserProcessSubThread> thread) {
   thread.reset();
 }
 
-NOINLINE void ResetThread_IndexedDb(std::unique_ptr<base::Thread> thread) {
-  volatile int inhibit_comdat = __LINE__;
-  ALLOW_UNUSED_LOCAL(inhibit_comdat);
-  thread.reset();
-}
-
 MSVC_POP_WARNING()
 MSVC_ENABLE_OPTIMIZE();
 
@@ -1314,10 +1308,6 @@ void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
           break;
       }
     }
-    {
-      TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IndexedDBThread");
-      ResetThread_IndexedDb(std::move(indexed_db_thread_));
-    }
 
     // Close the blocking I/O pool after the other threads. Other threads such
     // as the I/O thread may need to schedule work like closing files or
@@ -1402,9 +1392,6 @@ int BrowserMainLoop::BrowserThreadsStarted() {
   }
 #endif
 
-  indexed_db_thread_.reset(new base::Thread("IndexedDB"));
-  indexed_db_thread_->Start();
-
   HistogramSynchronizer::GetInstance();
 #if defined(OS_ANDROID) || defined(OS_CHROMEOS)
   // Up the priority of the UI thread.