Update TaskTraits in browser_main_loop.cc.

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 aed3789f7230625bd929d0c4a7decd3adfa30f0e..cc10db40fa88bb425a9b95f581cefe6179ed49be 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -1011,10 +1011,11 @@ int BrowserMainLoop::CreateThreads() {
 
     // Otherwise this thread ID will be backed by a SingleThreadTaskRunner using
     // |non_ui_non_io_task_runner_traits| (which can be augmented below).
-    // TODO(gab): Existing non-UI/non-IO BrowserThreads allow waiting so the
-    // initial redirection will as well but they probably don't need to.
+    // TODO(gab): Existing non-UI/non-IO BrowserThreads allow blocking and sync
+    // primitives so the initial redirection will as well but they probably
+    // don't need to.

[gab, 2016/12/21 16:16:57]

This TODO was meant to flag WithWait() being overkill for most tasks.

(i.e. remove "blocking and" as blocking is expected on to stay on these threads)

[fdoray, 2016/12/21 16:26:19]

Done.

     base::TaskTraits non_ui_non_io_task_runner_traits =
-        base::TaskTraits().WithFileIO().WithWait();
+        base::TaskTraits().MayBlock().WithSyncPrimitives();
 
     switch (thread_id) {
       case BrowserThread::DB: