Remove PostCrossThreadBind variant that operates over repeating callbacks

All users have been switched to using the variant of PostCrossThreadTask
and PostDelayedCrossThreadTask that operate on WTF's once-callbacks
(aka CrossThreadOnceFunction).

BUG=963574
R=haraken@chromium.org, hiroshige@chromium.org

Change-Id: I2ff3732924192f910ae26b810353efa84eafaf0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1626489
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686681}

third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h

@@ -14,13 +14,6 @@
 namespace blink {
 
 // For cross-thread posting. Can be called from any thread.
-inline void PostCrossThreadTask(base::SequencedTaskRunner& task_runner,
-                                const base::Location& location,
-                                WTF::CrossThreadClosure task) {
-  task_runner.PostDelayedTask(location, ConvertToBaseCallback(std::move(task)),
-                              base::TimeDelta());
-}
-
 inline void PostCrossThreadTask(base::SequencedTaskRunner& task_runner,
                                 const base::Location& location,
                                 WTF::CrossThreadOnceClosure task) {
@@ -28,14 +21,6 @@ inline void PostCrossThreadTask(base::SequencedTaskRunner& task_runner,
       location, ConvertToBaseOnceCallback(std::move(task)), base::TimeDelta());
 }
 
-inline void PostDelayedCrossThreadTask(base::SequencedTaskRunner& task_runner,
-                                       const base::Location& location,
-                                       WTF::CrossThreadClosure task,
-                                       base::TimeDelta delay) {
-  task_runner.PostDelayedTask(location, ConvertToBaseCallback(std::move(task)),
-                              delay);
-}
-
 inline void PostDelayedCrossThreadTask(base::SequencedTaskRunner& task_runner,
                                        const base::Location& location,
                                        WTF::CrossThreadOnceClosure task,