Make SequencedWorkerPool a TaskRunner

base/threading/sequenced_worker_pool.cc

Index: base/threading/sequenced_worker_pool.cc
diff --git a/base/threading/sequenced_worker_pool.cc b/base/threading/sequenced_worker_pool.cc
index 35028547ae41f2d6dfbff2f13209ce7d3bc8b414..3340cc334aa9c0630bcd7a03bf3c9845b74354d2 100644
--- a/base/threading/sequenced_worker_pool.cc
+++ b/base/threading/sequenced_worker_pool.cc
@@ -4,7 +4,6 @@
 
 #include "base/threading/sequenced_worker_pool.h"
 
-#include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
@@ -145,6 +144,21 @@ bool SequencedWorkerPool::PostSequencedWorkerTaskWithShutdownBehavior(
                         from_here, task);
 }
 
+bool SequencedWorkerPool::PostDelayedTask(
+    const tracked_objects::Location& from_here,
+    const Closure& task,
+    int64 delay_ms) {
+  // TODO(akalin): Add support for non-zero delays.
+  DCHECK_EQ(delay_ms, 0);
+  return PostWorkerTask(from_here, task);
+}
+
+bool SequencedWorkerPool::RunsTasksOnCurrentThread() const {
+  // TODO(akalin): Add support for this.

[brettw, 2012/02/24 05:25:51]

Can you clarify what this comment is trying to say? Also, I'm not sure the
NOTREACHED is necessary. According to the docs, the current behavior is valid,
and this is the type of thing that I suspect we won't get to soon. It will be
confusing for somebody to call RunsTasksOnCurrentThread and see an assertion
here.

[willchan no longer on Chromium, 2012/02/28 22:29:54]

I think we don't want people to call this function until we support it, since it
won't be doing the correct assertions. I guess there's a tradeoff here between
potentially having some people get confused about hitting a NOTREACHED() (and
then removing their assertion) vs people expecting an assertion to work, and
then having to fix a bunch of assertions later on when we implement this.

I think I prefer the former, since I don't want to place undue burden on the
implementer to fix all call sites later on.

I defer to Brett here.

[akalin, 2012/02/29 00:17:42]

Clarified comment.  I think I agree with willchan here.  I'll check this in now
(since you LGTMed it) and will work on actually implementing that function,
rendering this moot.

+  NOTREACHED();
+  return true;
+}
+
 void SequencedWorkerPool::FlushForTesting() {
   {
     AutoLock lock(lock_);